Impedanzrohr-System von BSWA

Transkript

1 INTELLIGENT TESTING EQUIPMENT Impedanzrohr-System von BSWA Impedanzrohre Die Impedanzrohre aus der BSWA SW Familie messen mit höchster Genauigkeit Schallabsorptionskoeffizienten sowie Impedanzen gemäß ISO und ASTM. Darüber hinaus unterstützen sie Transfer-Funktions-basierte Schalldämpfungsmessungen. Bei der Transfer-Funktions-basierten Messmethode wird aus der gemessenen Transferfunktion die Eingangsenergie aus der reflektierten Energie herausgerechnet. Danach können die akustischen Eigenschaften des im Impedanzrohr installierten Prüflings bestimmt werden. Die Impedanzrohre der SW Familie wurden explizit dafür entworfen, nicht nur mit klar vordefinierten Messdatensätzen sondern auch im Feld zu arbeiten. Die kompakten Abmessungen und die stabile Aluminiumkonstruktion sind beste Voraussetzungen für den mobilen Betrieb. Die SW Familie eignet sich hervorragend, um die akustischen Eigenschaften von Wänden, Decken, eingebauten Baumaterialien, Fahrbahnoberflächen, unterschiedlichen Bodenflächen, Innenräumen von Fahrzeugen und vielem mehr zu bestimmen. BSWA bietet eine vollständig ausgebaute Produktpalette von Impedanzrohren. Zum Lieferumfang gehören unter anderem die Rohre selbst, Mikrofone, Data Logger Hardware sowie die Messdatenerfassungs-Software. SPEZIFIKATION Standard GB/T-18696, , ISO , 1998, ASTM E Frequenzbereich (Hz) Ø des Rohrs innen Lautsprecher OPTIONEN 125 ~ ~ mm 60 & 30 mm 63 ~ ~ 6300 Modell SW230 SW260 SW420 SW470 SW422 SW477 Messwert Schalldämpfungskoeffizient (α) Schalldämpfungskoeffizient (α) und Übertragungsdämpfung(TL) Schallabsorptionsnormen: GB/T , , ISO , 1998; ASTM E ASTM E ~ ~ mm 30 mm 100 mm 30 mm 10,16 cm (4 ) Durchmesser, 20 Watt, 8 Ohm Modell SW230 SW230 SW420 SW470 SW422 SW477 6,35 mm MPA416 (1/4 ) Mikrofon Datenerfassungskarte Leistungsverstärker MC3022+PA50 oder MC3522 PA50 MC3242 Software VA-Lab2 Basic + VA-Lab2 IMP-A VA-Lab4 Basic + VA-Lab4 IMP-AT ROGA-Instruments, Im Hasenacker 56, Nentershausen Phone: +49 (0) , info@roga-messtechnik.de

2 BSWA Impedanzrohr Systemlösungen Pos. Menge SW 230 Beschreibung Einzelpreis Gesamt 1 1 SW230; Zur genauen Messung der Schallabsorptionskoeffizienten ( Hz), 60 mm Innendurchmesser, bestehend aus: - ein Rohr mit 60 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 60 mm 4.000, , MC3522; USB-Messkarte mit 2 ICP-Eingangskanälen und 1 Ausgangskanal; mit eingebauter Endstufe von 20 Watt 1.333, , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393,00 786, CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 116, CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 6 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 7 1 VA-Lab2 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 8 1 VA-Lab2 IMP-A; Software zur Messung von Schallabsorptionskoeffizienten (2 Mikrofone werden benötigt). 26,00 26,00 325,00 325,00 453,00 453,00 490,00 490,00 Frachtkosten CN > DE : 270,00 Zwischensumme : 7.799,00 Summe : 7.799,00 MwSt.: 19,00% 1.481,81 Gesamt : 9.280,81 Page 1 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

3 Pos. Menge SW 260 Beschreibung Einzelpreis Gesamt 1 1 SW260; Zur genauen Messung der Schallabsorptionskoeffizienten ( Hz), 60 mm Innendurchmesser, bestehend aus: - ein Rohr mit 30 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 30 mm - ein Rohr mit 60 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 60 mm 4.480, , MC3522; USB-Messkarte mit 2 ICP-Eingangskanälen und 1 Ausgangskanal; mit eingebauter Endstufe von 20 Watt 1.333, , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393,00 786, CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 116, CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 6 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 7 1 VA-Lab2 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 8 1 VA-Lab2 IMP-A; Software zur Messung von Schallabsorptionskoeffizienten (2 Mikrofone werden benötigt). 26,00 26,00 325,00 325,00 453,00 453,00 490,00 490,00 Frachtkosten CN > DE : 270,00 Zwischensumme : 8.279,00 Summe : 8.279,00 MwSt.: 19,00% 1.573,01 Gesamt : 9.852,01 Pos. Menge SW 420 Beschreibung Einzelpreis Gesamt 1 1 SW420; Zur genauen Messung der Schallabsorptionskoeffizienten ( Hz), 100 mm Innendurchmesser, bestehend aus: - ein Rohr mit 100 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 100 mm 4.000, , MC3522; USB-Messkarte mit 2 ICP-Eingangskanälen und 1 Ausgangskanal; mit eingebauter Endstufe von 20 Watt 1.333, , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393,00 786, CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 116, CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 6 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 7 1 VA-Lab2 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 8 1 VA-Lab2 IMP-A; Software zur Messung von Schallabsorptionskoeffizienten (2 Mikrofone werden benötigt). 26,00 26,00 325,00 325,00 453,00 453,00 490,00 490,00 Frachtkosten CN > DE : 270,00 Zwischensumme : 7.799,00 Summe : 7.799,00 MwSt.: 19,00% 1.481,81 Gesamt : 9.280,81 Page 2 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

4 Pos. Menge SW 470 Beschreibung Einzelpreis Gesamt 1 1 SW470; Zur genauen Messung der Schallabsorptionskoeffizienten ( Hz), 30 mm Innendurchmesser, bestehend aus: - ein Rohr mit 30 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 30 mm 3.400, , MC3522; USB-Messkarte mit 2 ICP-Eingangskanälen und 1 Ausgangskanal; mit eingebauter Endstufe von 20 Watt 1.333, , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393,00 786, CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 116, CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 6 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 7 1 VA-Lab2 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 8 1 VA-Lab2 IMP-A; Software zur Messung von Schallabsorptionskoeffizienten (2 Mikrofone werden benötigt). 26,00 26,00 325,00 325,00 453,00 453,00 490,00 490,00 Frachtkosten CN > DE : 270,00 Zwischensumme : 7.199,00 Summe : 7.199,00 MwSt.: 19,00% 1.367,81 Gesamt : 8.566,81 Page 3 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

5 Pos. Menge SW 433 Beschreibung Einzelpreis Gesamt 1 1 SW433; Zur genauen Messung von Schallabsorptionskoeffizienten ( Hz) und Materialimpedanzwerten ( Hz), 60mm Innendurchmesser, gehören: - ein Rohr mit 60 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 60 mm - ein Verlängerungsrohr mit einem Durchmesser von 60 mm 5.170, , PA50; 50W Endverstärker 570,00 570, MC3242; DAQ-Karte mit 4 ICP-Eingangskanälen und 2 Signalausgangskanälen, USB-Stromversorgung, 0-20kHz, mit Laptop zu verbinden , , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393, , CBB005; BNC zu BNC Kabel, 5m, um PA50 mit MC3242 zu verbinden 32,00 32,00 4 CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 232,00 1 CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 1 VA-Lab4 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 1 VA-Lab4 IMP-A; Software zur Messung von Materialimpedanzwerten (4 Mikrofone werden benötigt), zur Messung der Übertragungsfunktion und zur Berechnung von Schallimpedanzkoeffizienten und Schallimpedanz. 26,00 26,00 325,00 325,00 760,00 760,00 720,00 720,00 Frachtkosten CN > DE : 270,00 Zwischensumme : ,00 Summe : ,00 MwSt.: 19,00% 2.406,73 Gesamt : ,73 Page 4 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

6 Pos. Menge SW 463 Beschreibung Einzelpreis Gesamt 1 1 SW463; Zur genauen Messung von Schallabsorptionskoeffizienten ( Hz) und Materialimpedanzwerten ( Hz), 30mm und 60mm Innendurchmesser, gehören: - ein Rohr mit 60 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 60 mm - ein Rohr mit 30 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 30 mm - ein Verlängerungsrohr mit einem Durchmesser von 60 mm 5.720, , PA50; 50W Endverstärker 570,00 570, MC3242; DAQ-Karte mit 4 ICP-Eingangskanälen und 2 Signalausgangskanälen, USB-Stromversorgung, 0-20kHz, mit Laptop zu verbinden , , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393, , CBB005; BNC zu BNC Kabel, 5m, um PA50 mit MC3242 zu verbinden 32,00 32,00 4 CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 232,00 1 CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 1 VA-Lab4 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 1 VA-Lab4 IMP-A; Software zur Messung von Materialimpedanzwerten (4 Mikrofone werden benötigt), zur Messung der Übertragungsfunktion und zur Berechnung von Schallimpedanzkoeffizienten und Schallimpedanz. 26,00 26,00 325,00 325,00 760,00 760,00 720,00 720,00 Frachtkosten CN > DE : 270,00 Zwischensumme : ,00 Summe : ,00 MwSt.: 19,00% 2.511,23 Gesamt : ,23 Page 5 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

7 Pos. Menge SW 466 Beschreibung Einzelpreis Gesamt 1 1 SW466; Zur genauen Messung von Schallabsorptionskoeffizienten 6.180, ,00 ( Hz) und Übertragungsverlust ( Hz), 30mm und 60mm Innendurchmesser, beinhaltet: - ein Rohr mit 60 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 60 mm - ein Rohr mit 30 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 30 mm - ein Verlängerungsrohr mit einem Durchmesser von 60 mm - ein Verlängerungsrohr mit einem Durchmesser von 30 mm 2 1 PA50; 50W Endverstärker 570,00 570, MC3242; DAQ-Karte mit 4 ICP-Eingangskanälen und 2 Signalausgangskanälen, USB-Stromversorgung, 0-20kHz, mit Laptop zu verbinden , , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393, , CBB005; BNC zu BNC Kabel, 5m, um PA50 mit MC3242 zu verbinden 32,00 32,00 4 CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 232,00 1 CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 1 VA-Lab4 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 1 VA-Lab4 IMP-A; Software zur Messung von Materialimpedanzwerten (4 Mikrofone werden benötigt), zur Messung der Übertragungsfunktion und zur Berechnung von Schallimpedanzkoeffizienten und Schallimpedanz. 26,00 26,00 325,00 325,00 760,00 760,00 720,00 720,00 Frachtkosten CN > DE : 270,00 Zwischensumme : ,00 Summe : ,00 MwSt.: 19,00% 2.598,63 Gesamt : ,63 Page 6 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

8 Pos. Menge SW 422 Beschreibung Einzelpreis Gesamt 1 1 SW422; Zur genauen Messung von Schallabsorptionskoeffizienten ( Hz) und Materialimpedanzwerten ( Hz), 100mm Innendurchmesser, beinhaltet: - ein Rohr mit 100 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 100 mm - ein Verlängerungsrohr mit einem Durchmesser von 100 mm 4.480, , PA50; 50W Endverstärker 570,00 570, MC3242; DAQ-Karte mit 4 ICP-Eingangskanälen und 2 Signalausgangskanälen, USB-Stromversorgung, 0-20kHz, mit Laptop zu verbinden , , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393, , CBB005; BNC zu BNC Kabel, 5m, um PA50 mit MC3242 zu verbinden 32,00 32,00 4 CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 232,00 1 CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 1 VA-Lab4 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 1 VA-Lab4 IMP-A; Software zur Messung von Materialimpedanzwerten (4 Mikrofone werden benötigt), zur Messung der Übertragungsfunktion und zur Berechnung von Schallimpedanzkoeffizienten und Schallimpedanz. 26,00 26,00 325,00 325,00 760,00 760,00 720,00 720,00 Frachtkosten CN > DE : 270,00 Zwischensumme : ,00 Summe : ,00 MwSt.: 19,00% 2.275,63 Gesamt : ,63 Page 7 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

9 Pos. Menge SW 477 Beschreibung Einzelpreis Gesamt 1 1 SW477; Zur genauen Messung von Schallabsorptionskoeffizienten ( Hz) und Materialimpedanzwerten ( Hz), 30mm Innendurchmesser, beinhaltet: - ein Rohr mit 30 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 30 mm - ein Verlängerungsrohr mit einem Durchmesser von 30 mm 3.880, , PA50; 50W Endverstärker 570,00 570, MC3242; DAQ-Karte mit 4 ICP-Eingangskanälen und 2 Signalausgangskanälen, USB-Stromversorgung, 0-20kHz, mit Laptop zu verbinden , , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393, , CBB005; BNC zu BNC Kabel, 5m, um PA50 mit MC3242 zu verbinden 32,00 32,00 4 CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 232,00 1 CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 1 VA-Lab4 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 1 VA-Lab4 IMP-A; Software zur Messung von Materialimpedanzwerten (4 Mikrofone werden benötigt), zur Messung der Übertragungsfunktion und zur Berechnung von Schallimpedanzkoeffizienten und Schallimpedanz. 26,00 26,00 325,00 325,00 760,00 760,00 720,00 720,00 Frachtkosten CN > DE : 270,00 Zwischensumme : ,00 Summe : ,00 MwSt.: 19,00% 2.161,63 Gesamt : ,63 Page 8 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

10 Pos. Menge SW422 + SW477 Beschreibung Einzelpreis Gesamt 1 1 SW422 + SW477; Zur genauen Messung der Schallabsorptionskoeffizienten ( Hz) und der Übertragungsdämpfung ( Hz), einschließlich: - ein Rohr mit 100 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 100 mm - ein Verlängerungsrohr mit einem Durchmesser von 100 mm - ein Rohr mit 30 mm Durchmesser - ein Probenhalter mit einem Durchmesser von 30 mm - ein Verlängerungsrohr mit einem Durchmesser von 30 mm 8.360, , PA50; 50W Endverstärker 570,00 570, MC3242; DAQ-Karte mit 4 ICP-Eingangskanälen und 2 Signalausgangskanälen, USB-Stromversorgung, 0-20kHz, mit Laptop zu verbinden , , MPA416; 1/4" Mikrofon mit ICP Vorverstärker 393, , CBB005; BNC zu BNC Kabel, 5m, um PA50 mit MC3242 zu verbinden 32,00 32,00 4 CBS005 BNC - SMB Kabel, 5 Meter, um MPA416 an MC3522 anzuschließen 58,00 232,00 1 CAA002; 2 Meter Kabel Bananenstecker zum Anschluss des MC3522 an den Lautsprecher der Impedanzröhre. 1 CA115; Schalldruck-Kalibrator / Schallpegelkalibrator; Entspricht IEC Klasse 2 für 1" und 1/2" & 1/4 - Mikrofonkapsel. Mit quarzgesteuertem Oszillator zum Überprüfen der Genauigkeit bei Schallpegel-Messgeräten nach IEC Klasse Hz Ausgabepegel. 1 VA-Lab4 BASIC; Zwei Kanal Basissoftware zur Messung von Schall und Schwingung. 1 VA-Lab4 IMP-A; Software zur Messung von Materialimpedanzwerten (4 Mikrofone werden benötigt), zur Messung der Übertragungsfunktion und zur Berechnung von Schallimpedanzkoeffizienten und Schallimpedanz. 26,00 26,00 325,00 325,00 760,00 760,00 720,00 720,00 Frachtkosten CN > DE : 270,00 Zwischensumme : ,00 Summe : ,00 MwSt.: 19,00% 3.012,83 Gesamt : ,83 Download BSWA Gesamtkatalog PDF Mit weiteren Produkten wie Sphärische Oberflächenbefestigung für Schallleistung, Impedanzrohre, Mikrofon Arrays und vieles mehr. Page 9 of 9 Vorherige Preislisten sind nicht länger gültig. Preise und Konditionen können sich ohne Ankündigung ändern. Alle Preise verstehen sich als UVP. ohne aktuelle MwSt.

11 5.4 Impedance Tube VA-Lab I MP is the software s pecifically designed by B SWA for measurement of absorption coefficient and transmission loss of material. The hardware is based on BSWA SW series impedance tubes. VA-Lab2 IMP supports the 2-channel hardware and can be used in the measurement of absorption coefficient; VA-Lab4 IMP supports four microphones transfer function method not only for absorption measurement but also for sound insulation measurement. It uses the formula in published paper to calculate the transmission loss by adding an extension tube. Three modules can be chosen in VA-Lab IMP in according to the difference requirement of standard. VA-Lab IMP conforms to the following standards: ISO : 1996 Acoustics-Determination of sound absorption coefficient and impedance in impedance tubes-part1: Method using standing wave ratio ISO : 1998 Acoustics-Determination of sound absorption coefficient and impedance in impedance tubes-part2: Transfer function method E Standard Test Method for Impedance and Absorption of Acoustical Materials Using A tube, Two Microphones and A Digital Frequency Analysis. E Standard Test Method for Measurement of Normal Incidence Sound Transmission of Acoustical Materials Based on the Transfer Matrix Method. Transmission Loss is based on F our-microphone Transfer-function method and the ISO standard is under discussion. The impedance tube system is developed on BSWA digital acquisition hardware with the developing platform of LabVIEW. 31

12 5.4.1 Method using standing wave ratio The S tanding Wave R atio ( SWR) i s a t raditional method, w hich nee ds t o generate a standing wave in the impedance tube. VA-Lab can calculate the absorption coefficients by capturing the maximum and minimum value of the sound pressure in the tube. The other acoustic par ameters s uch as r eflectance c oefficient, i mpedance r atio, and adm ittance ratio can be calculated based on the first minimum position of the pressure. Before running the test system, the hardware should be set up as the graph below (Using MC3522 with built-in power amplify for example) PC USB INPUTS MC3522 USB AMP SIGNAL GAIN OUTPUT Speaker Microphone Menu Item: Application//Impedance Tube List Item: Method using standing wave rate To capture the sound pressure level in tube, only one channel is needed. Set the chosen channel, an d c hoose t he f requency und er t est, t hen s tart m easurement by c licking <Run>. 32

13 The frequencies under t est can b e t he c entre frequencies of octave or 1/3 oc tave by choosing Type in the left-bottom of the window. If user-defined are chosen, the test frequency need to be input into the table one by one. Hint: do not to change the frequencies after starting measurement in order to avoid error Test Process: a. Choose a frequency in the table, for example, 200Hz (as the graph above) b. Click <Run>, program will generate a 200Hz pure tone, and the sound pressure level of t he pr obe po sition i n t he t ube w ill be s hown. Increase t he out put of t he pow er amplifier to avoid the disturbance of the background noise. c. Move the position of the microphone probe s port slowly. Notice the change of the sound pressure level especially the first minimum value. d. When the first maximum vale and the first minimum value are captured, Click <Stop> to stop the measurement and the absorption will be shown in the left-hand table. The captured values are shown in the middle-bottom of the window. In the processing of test, Click <reset> to recalculate the Max and Min Value if needed e. Change the test frequency and repeat a-d. f. After a ll t he frequencies are t ested, c lick <Graph> to c heck t he s pectrum of absorption of the material g. If the positions of the first minimum vale are record, click <Others> to calculate the other sound parameter, including reflectance coefficient, impedance ratio, and admittance ratio, etc. 33

14 5.4.2 Transfer function method The Transfer Function Method uses two fixed microphones to acquire pressure which is produced by a sound source near the sample. VA-Lab IMP can accurately separate the incident wave from reflecting wave and calculate the absorption coefficient. An extended frequency range can be obtained from the combination of measurement results gained from the tubes of different diameters. The test system can measure acoustic properties of material simultaneously in a wide frequency range of interest Setup Before running the test system, the hardware should be set up. Figure 1 gi ves t he setup of abs orption c oefficient t esting s ystem (Using MC 3522 with built-in power amplify for example) and, Figure 2 gives the setup of transmission loss measurement system (Using MC3242, PA50, for example). MC3522 INPUTS 1 2 USB AMP SIGNAL GAIN OUTPUT USB SWxxx-L SWxxx-S Figure1: System connection of absorption coefficient testing (xxx is the type of the tube, including 030,060,100) 34

15 To measure the absorption coefficient of material, Source Tube and Sample Holder are necessary. T he r ight c onfigurations are: S W100-L/SW100-S, S W060-L/SW060-S, SW030-L/SW030-S (Find more details in : BSWA SW xxx-series Impedance Tube). SWxxx-L SWxxx-E Figure 2: System connection of transmission loss testing (xxx is the type of the tube, including 030,060,100) To measure insulation coefficient of material, Source Tube and Extension Tube are necessary. T he r ight c onfigurations are: S W100-L/SW100-E, S W060-L/SW060-E, SW030-L/SW030-E(Find m ore det ails i n Appendix: B SWA SW xx x-series I mpedance Tube). 35

16 Software Operation Menu Item: Application//Impedance Tube List Item: Transfer function method (ISO) The figure above shows the type of current measurement: Absorption Measurement. See red frame. 36

17 Test Process: 1 Click <Setting> to Choose the tube type and set the environment parameter. In the graph below, the upper is the setting of Absorption Measurement and the lower is the setting window of Insulation Measurement. There are three items need to be set. 37

18 Mode Choose: Choose Absorption coefficient measurement or Transmission Loss measurement. Mode must be c hosen firstly because i t d ecides t he c ontent o f t he measurement. TUBE: Select t he t ype of t ube t o be us ed f or t esting, t he par ameter c an be gi ven automatically if the BSWA SW xxx-series impedance tube is used, involving the distance between two microphones, the distance from the sample to the nearest microphone, the tube di ameter and ef fective f requency r ange. The dat a w hich i s not i ncluded i n t he working frequency range will be inaccurate. To get full-band results, the tubes with different inner diameter should be used together. BSWA offers three kinds of tubes, among which 100mm and 60mm tube have two position groups of two microphones. In the graph above, measurement can use Position 1/2 or Position 0/2, the latter is called wide spacing. For the tubes which are not offered by BSWA, User-defined tube can be used. If user-defined is chosen, the parameters such as the tube diameter, the distance between two microphones, the distance from the sample to the nearest microphone and frequency r ange c an be m odified. T he t heoretic r ange i s al so gi ven. T he w orking frequency must be in the range of the theoretic range. ENVIRONMENT: Fill t he at mospheric pr essure,temperature an d r elative humidity t o calculate the air density, sound velocity and c haracteristic impedance of air. The default value of atmospheric pr essure, temperature and h umidity i s Pa, 20 and 50% respectively. If Transmission Loss measurement is chosen, Thickness of the sample(m) should be filled in the actual value. 38

19 2. Click <Measurement> to start measurement in the given frequency range. To get accurate results in the given frequency, the measurement should be processed two times. In the absorption coefficient measurement, the positions of the microphones are interchanged t o el iminate t he er ror br ought by t he di fference of m icrophone phas e ( In transmission loss measurement, the state of extension tube end is different in two tests). In the measurement window, Green and Red denote the two situations of testing. For Absorption coefficient measurement a. According to, be sure that the microphone in Channel 1 near to the source and the microphone in channel 2 near to the sample. b. Press <Run> to start measurement,when the curve becomes smooth, click <Stop>. c. Click change to d. Exchange the position of two microphones as, be sure that the microphone in Channel2 near to the source and the microphone in channel1 near to the sample. e. Repeat b f. Click <Results> after finishing the two measurements. 39

20 For Transmission Loss measurement a. According Figure 2, connect the 4-channel hardware and the tube, be sure the color of the block is green: and with the extension tube open ended; b. Press <Run> to start measurement,when the curve becomes smooth, click <Stop>; c. Click change to ; d. Be sure that the extension tube is closed ended; e. Repeat b; f. Click <Results> after finishing the two measurements; 40

21 g. The Result will be shown and checked in page Current result after Click <Results> in page Measurement. It is recommended that one sample should be tested at least 3 times to get an average result. The result can be added to average list, click <Add to Average> h. Return to page Measurement, relocate the sample and repeat a-f; i. A ll t he added r esults are s hown i n gr aph i n pa ge Average Result. Clic k < Average result> to get the average result (red curve in graph) and the average result table. 41

22 j. Save the last result by choosing the data type below Export Operation. (If in page Current Result, this operation will save the current result) Hints: 1) The longer of test time it takes to measure in page Measurement, the smoother the curve becomes and the more precise the result is. 2) Please pay attention to the corresponding relationship between the positions of the microphones and color block. 3) T est t he bac kground noi se w hen t he s ignal gener ator i s t urned o ff. T he s ignal amplitude shall be at least 10dB higher than the background noise at all frequencies of interest. I t w ill b e go od t he s ound pr essure level is bet ween 90 db a nd 1 10dB at t he chosen microphone locations. 4) If an external signal generator is used, cancel the choice of With Generator. 3. Test with different tubes. For t he di fferent f requency band, t he c hoice of t ube s hould be c hanged i n <Setting> window. Repeat 1, 2, and save the last result of each frequency band. To get the result of full band, the chose tube would be Large Tube, Wide Spacing Large Tube and Small Tube. For the former tube the chose tube could be Medium Tube, Wide Spacing Medium and Small Tube. Choose the Tube according to the actual impedance tube used. 42

23 4. Click <Data Analysis> to check, compare and combine the previously saved results of different frequency bands. k. Click <Load> to c hoose t he r esult ne eded t o c ombine. The dat a w hich will be combined should accord with the title in front of <Load>, Or else, the combined result is wrong. In general, there are 3 r esults of different frequency range. in front of <Load> is to control the display of loaded data and the data needed to combine; in front of <Combine> is to control the display of combined data. l. Click <Combine> to combine the chosen curves. m. Save the combined result by choosing the data type below Export Operation n. <Graph Show> is used to build the curve of data in table o. For sound absorption coefficient measurement, practical sound absorption coefficient and w eighted s ound a bsorption coefficient c an b e c alculated by clicking <Rating> according to ISO 11654:1997. p. Click <Report> to fill in the information of martial and measurement, and all of them 43

24 can be export to EXCEL as result report. q. In page Data Comparison, the different testing data can be loaded and shown in one figure. At most 10 groups can be compared in one time Notices According to the standard, the loudspeaker should work at least 10 minutes before testing materials. Because the different positions of microphones work in different effectual frequency range, curves out of the range will be random. Green mode and red mode have no order in measurement, but the connection must be corresponding with the mode. The test sample shall fit snugly in the holder. However it shall not be compressed unduly nor fitted so tightly that it bulges. It is recommended to fill in the interspaces by using Vaseline or Plasticine between the sample and the tube. The test sample can be held firmly, if necessary, by adhesive tape or grease. For example, samples such as carpet m aterial s hould b e f irmly at tached t o t he bac k p late us ing dou ble-sided adhesive tape to avoid vibration and unwanted air gaps. Most of the specimen, even the uniform one, should be tested repeatedly. Absorption coefficient of the same sample in different diameter tubes will be dissimilar mostly because of the dimension of the specimens and t he situation of specimens edge. Uncertainties to the determined acoustic material properties would come from material samples and placement, bias errors and reference plane definition. 44

25 BSWA SW xxx-series Impedance Tube Types only support Absorption Coefficient Measurement SW 420 (63Hz~1600Hz) consists of: SW100-L: a 100mm diameter tube with build-in loud speaker SW100-S: a 100mm diameter sample holder (Microphones are separately sold, the same below) SW100-L SW100-S Test Sample Specifications: Source Tube (SW100-L) inner diameter:100mm Loudspeaker:4 diameter,20watts,8ω,working frequency:20hz ~ 8000Hz Distance between Mic2 and sample:50mm Distance between Mic1 and Mic2:80mm (Choose Large Tube in setting of software when microphone positions are Mic1 and Mic2, and the Absorption coefficient frequency range is 250Hz ~ 1600Hz) Distance between Mic0 and Mic2:300mm (Choose Wide Spacing Large Tube in setting of software when microphone positions are Mic0 and Mic2, and the Absorption coefficient frequency range is 63Hz ~ 500Hz) Sample Holder(SW100-S) for material thickness:0 200mm 45

26 SW 430 (100Hz~2500Hz) consists of: SW060-L: a 60mm diameter tube with build-in loud speaker SW060-S: a 60mm diameter sample holder SW060-L Test Sample SW060-S Specifications: Source Tube (SW060-L) inner diameter:60mm Loudspeaker:4 diameter,20watts,8ω,working frequency:20hz ~ 8000Hz Distance between Mic2 and sample:35mm Distance between Mic1 and Mic2:45mm (Choose Medium Tube in setting of software when microphone positions are Mic1 and Mic2, and the Absorption coefficient frequency range is 400Hz ~ 2500Hz) Distance between Mic0 and Mic2:170mm (Choose Wide Spacing Medium Tube in setting of software when microphone positions are Mic0 and Mic2, and the Absorption coefficient frequency range is 100Hz ~ 800Hz) Sample Holder (SW060-S) for material thickness:0 100mm 46

27 SW 470 (1000Hz~6300Hz) consists of: SW030-L: a 30mm diameter tube with build-in loud speaker SW030-S: a 30mm diameter sample holder 5 6 SW030-L Test Sample SW030-S Specifications: Source Tube (SW030-L) inner diameter:30mm Loudspeaker:2 diameter,3watts,8ω,working frequency:200hz ~ 8000Hz Distance between Mic6 and sample:15mm Distance between Mic5 and Mic6:22.5mm (Choose Small Tube in setting of software when microphone positions are Mic5 and Mic6, and the Absorption coefficient frequency range is 1000Hz ~ 6300Hz) Sample Holder (SW030-S) for material thickness:100mm SW 260 (100Hz~6300Hz) consists of: SW060-L: a 60mm diameter tube with build-in loud speaker SW060-S: a 60mm diameter sample holder SW030-L: a 30mm diameter tube with build-in loud speaker SW030-S: a 30mm diameter sample holder SW 270 (63Hz~6300Hz) consists of: SW100-L: a 100mm diameter tube with build-in loud speaker SW100-S: a 100mm diameter sample holder SW030-L: a 30mm diameter tube with build-in loud speaker SW030-S: a 30mm diameter sample holder 47

28 Types support Absorption Coefficient and Transmission Loss Measurement SW 422 (63Hz~1600Hz) consists of: SW100-L: a 100mm diameter tube with build-in loud speaker SW100-S: a 100mm diameter sample holder SW100-E: a 100mm diameter extension tube SW100-L Test Sample SW100-S SW100-L Sample Surface SW100-E End 48

29 Specifications: Source Tube (SW100-L) inner diameter:100mm Loudspeaker:4 diameter,20watts,8ω,working frequency:20hz ~ 8000Hz Distance between Mic2 and sample:50mm Distance between Mic1 and Mic2:80mm (Choose Large Tube in setting of software when microphone positions are Mic1 and Mic2, and the Absorption coefficient frequency range is 250Hz ~ 1600Hz) Distance between Mic0 and Mic2:300mm (Choose Wide Spacing Large Tube in setting of software when microphone positions are Mic0 and Mic2, and the Absorption coefficient frequency range is 63Hz ~ 500Hz) Sample Holder (SW100-S) for material thickness:0 200mm Extension tube (SW100-E) inner diameter:100mm Distance between Mic3 and sample surface:150mm Distance between Mic3 and Mic4:80mm (Choose Large Tube in setting of software when microphone positions are Mic1, Mic2, Mic3 and Mic4, and the Transmission loss frequency range is 250Hz ~ 1600Hz) Distance between Mic3 and Mic9:300mm (Choose Wide Spacing Large Tube in setting of software when microphone positions are Mic0, Mic2, Mic3 and Mic9, and the Transmission loss frequency range is 63Hz ~ 500Hz) Sample Diameter:100mm Material thickness:<120mm 49

30 SW 433 (100Hz~2500Hz) consists of: SW060-L: a 60mm diameter tube with build-in loud speaker SW060-S: a 60mm diameter sample holder SW060-E: a 60mm diameter extension tube SW060-L Test Sample SW060-S SW060-L Sample Surface SW060-E End 50

31 Specifications: Source Tube (SW060-L)inner diameter:60mm Loudspeaker:4 diameter,20watts,8ω,working frequency:20hz ~ 8000Hz Distance between Mic2 and sample:35mm Distance between Mic1 and Mic2:45mm (Choose Medium Tube in setting of software when microphone positions are Mic1 and Mic2, and the Absorption coefficient frequency range is 400Hz ~ 2500Hz) Distance between Mic0 and Mic2: 170mm (Choose Wide Spacing Medium Tube in setting of software when microphone positions are Mic0 and Mic2, and the Absorption coefficient frequency range is 100Hz ~ 800Hz) Sample Holder (SW060-S) for material thickness:0 100mm Extension tube (SW060-E ) inner diameter:60mm Distance between Mic3 and sample surface:100mm Distance between Mic3 and Mic4:45mm (Choose Medium Tube in setting of software when microphone positions are Mic1, Mic2, Mic3 and Mic4, and the Transmission loss frequency range is 400Hz ~ 2500Hz) Distance between Mic3 and Mic9:170mm (Choose Wide Spacing Medium Tube in setting of software when microphone positions are Mic0, Mic2, Mic3 and Mic9, and the Transmission loss frequency range is 100Hz ~ 800Hz) Sample Diameter:60mm Material thickness:<80mm 51

32 SW 477 (1000Hz~6300Hz) consists of: SW030-L: a 30mm diameter tube with build-in loud speaker SW030-S: a 30mm diameter sample holder SW030-E: a 30mm diameter extension tube 5 6 SW030-L Test Sample SW030-S SW030-L Sample Surface SW030-E End Specifications: Source Tube (SW030-L) inner diameter:30mm Loudspeaker:2 diameter,3watts,8ω,working frequency:200hz ~ 8000Hz Distance between Mic6 and sample:15mm Distance between Mic5 and Mic6:22.5mm (Choose Small Tube in setting of software when microphone positions are Mic5 and Mic6, and the Absorption coefficient frequency range is 1000Hz ~ 6300Hz) Sample Holder (SW030-S) for material thickness:100mm Extension tube (SW030-E) inner diameter:30mm Distance between Mic7 and sample surface:100mm Distance between Mic7 and Mic8:22.5mm (Choose Small Tube in setting of software when microphone positions are Mic5, Mic6, Mic7 and Mic8, and the Transmission Loss frequency range is 1000Hz ~ 6300Hz) Sample Diameter:30mm Material thickness:<80mm 52

33 5.4.3 Transfer function method (ASTM) The Transfer Function Method uses two fixed microphones to acquire pressure which is produced by a sound source near the sample. VA-Lab IMP can accurately separate the incident wave from reflecting wave and calculate the absorption coefficient. An extended frequency range can be obtained from the combination of measurement results gained from the tubes of different diameters. The test system can measure acoustic properties of material simultaneously in a wide frequency range of interest. This module conforms to the following standards: E Standard Test Method for Impedance and Absorption of Acoustical Materials Using A tube, Two Microphones and A Digital Frequency Analysis. E Standard T est M ethod f or M easurement of Normal I ncidence S ound Transmission of Acoustical Materials Based on the Transfer Matrix Method Set up Before running the test system, the hardware should be set up. Figure 1 gi ves t he setup of abs orption c oefficient t esting s ystem (Using MC 3522 with built-in power amplify for example) and, Figure 2 gives the setup of transmission loss measurement system (Using MC3242, PA50, for example). INPUTS 1 2 MC3522 USB AMP GAIN OUTPUT U SWxxx-L SWxxx-S Figure1: System connection of absorption coefficient testing 53

34 PA50 MC3242 OUTPUTS INP SWxxx-L SWxxx-T SWxxx-E Figure 2: System connection of transmission loss testing The 2-Channel DA MC3522/MC3622 has build-in power amplifier, so it can connect with the source tube directly. The 4-channel DA has the output without amplification. It should connect the source tube with an external power amplifier. In addition, if the 4-Channel DA is used to measure the absorption coefficient, the first two channels are adopted. To measure the absorption coefficient of material, Source Tube and Sample Holder are necessary. T he r ight c onfigurations are: S W101-L/SW100-S, SW 061-L/SW060-S, SW031-L/SW030-S, SW016-L/SW016-S (Find more det ails i n : BSWA SW xxx-series Impedance Tube). To measure insulation coefficient of material, Source Tube and Extension Tube are necessary. The right configurations are: SW101-L/SW101T/SW101-E, SW061-L/SW061T /SW061-E, SW031-L/SW031T/SW031-E, SW016-L/SW016T/SW016-E (Find more details in : BSWA SW xxx-series Impedance Tube). 54

35 Software Operation Menu Item: Application//Impedance Tube List Item: Transfer function method (ASTM) The pi cture i n t he upp er of t he w indow s hows t he t ype of c urrent m easurement: Absorption Measurement. 55

36 Test Process: 1 Test Setting Click <Edit> to Change the tube type and set the environment parameter. In the graph below, the upper is the setting of Absorption Measurement and the lower is the setting window of Insulation Measurement. There are three items need to be set. 56

37 Mode Choose: Choose Absorption coefficient measurement or Transmission measurement. Mode must be c hosen firstly because i t d ecides t he c ontent o f t he measurement. TUBE: Select t he t ype of t ube t o be us ed f or t esting, t he par ameter c an be gi ven automatically if the BSWA SW xxx-series impedance tube is used, involving the distance between two microphones, the distance from the sample to the nearest microphone, the tube di ameter and ef fective f requency r ange. The dat a w hich i s not i ncluded i n t he working frequency range will be inaccurate. To get full-band results, the tubes with different inner diameter should be used together. BSWA offers three kinds of tubes, among which 100mm and 60mm tube have two position groups of two microphones. In the graph above, measurement can use Position 1/2 or Position 0/2, the latter is called wide spacing. For the tubes which are not offered by BSWA, User-defined tube can be used. If user-defined is chosen, the parameters such as the tube diameter, the distance between two microphones, the distance from the sample to the nearest microphone and frequency r ange c an be m odified. T he t heoretic r ange i s al so gi ven. T he w orking frequency must be in the range of the theoretic range. ENVIRONMENT: Fill t he at mospheric pr essure,temperature and r elative humidity t o calculate the air density, sound velocity and c haracteristic impedance of air. The default value of atmospheric pr essure, temperature and h umidity i s Pa, 20 and 50% respectively. If Transmission Loss measurement is chosen, Thickness of the sample (m) should be filled in the actual value. The sample must be placed in the specimen slot, and aligning the side near the source tube. Click <OK> to save the changed setting and click <Cancel> to exit the setting window without changing. 2 Channel Calibration Calibration is to correct t he measured transfer function data for mismatch in both the amplitude and phase responses of the two measurement channels. The information of the calibration is shown in the bottom of the main window. It must be done before the test of specimen. Click <Channel Calibration> to enter the interface of calibration. Hint: Software will show calibrated as long as the calibrated file of current tube exists. If the microphone connecting the test channels are changed or the system is lay up f or a long time, the calibration should be done again before the specimen s measurement. 57

38 There are two functions in this window. One is to measure the signal-to noise ratio (SNR). It is useful to adjust the output of the sound source in order to generate sufficient signal at both microphone locations such that the measured signal in each test frequency band is least 10 db greater than the background noise. In page Signal-to-Noise Ratio, when click <Start>, t here i s not s ignal o utput at first and t he test r esult is t he background noise. Several seconds later, the instrument start to phonate, then adjust the output of power amplifier to meet the requirement of SNR. After that, click <Stop> to end the test and keep the position of the knob of the power amplifier. If the external signal generator is adopted, the sound source must be switched on after the hint in the top of the window changed from Background noise test to signal test. 58

39 Since the transfer is a complex ratio of the acoustic pressure responses, any mismatch in the amplitude or phase response of the two microphone systems will affect the accuracy of the transfer function measurement. The following sequence of the measurement and computations pr ovides a m eans f or correcting the m easured t ransfer d ata i n bot h measurement channels. Step1- Place a highly absorptive specimen in t he t ube t o pr event s trong ac oustic reflections and to obtain the most accurate correction factor possible. Then choose Page Step 1 a s the graph above, c lick <Start> to measure the transfer functions. When the shown curve begins to smooth, click <Stop> and the test data will be saved automatically. Step2- Choose Page Step 2, and exchange the positions of the two microphones as the graph in Page Step 2, then measure the transfer functions again. The order o f t he t wo steps i s r andom, but i t must be ens ured t hat t he microphone s positions ar e accordance w ith t he picture i n c hosen page. The r esult of r epeated measurement will be recovered. Hint: If the external signal generator is adopted, It must be phonating in the whole time of calibration. 59

40 The interface of calibration for transmission test is similar with the one for absorption test except: The test of Signal-to-Noise Ratio needs to detect the signal at four microphone locations, and there are 3 microphone pairs need to measure the two transfer functions using the same computational algorithms: channel 1 to channel 2, channel3 and channel 4. That is to say, there ar e s ix t ransfer f unctions to be t est. The t est pr ocess i s s ame w ith t he description above, it is unnecessary to go into details here. 3.Sample Test Click <Sample Test> to enter the window of specimen measurement after finishing the channel calibration. The following sequence of measurements is for absorption coefficient measurement. a. Ensure that the microphone in Channel 1 near to the source and the microphone in channel 2 near to the sample, and the unused microphone port should be plugged up. Place the specimen under test to the sample holder. The face to the sound source should be flush with the mouth of holder, and there is not blank between the specimen and the bac king p late except s imulating a s uspended c eiling t ile. In addi tion, f or sponge m aterial t he s pecimen s hould not be compressed in t he hol der. You c an adjust the sample holder with the thickness of the specimen. 60

41 b. Press <Start measurement > to start measurement,and click <Stop measurement> until the curve becomes smooth. c. Click <Show Result> to check the result in page [Current Result] d. Page [Current Result] gives all kinds of results in current result. The spectrum type can be chosen in the right-hand of the window. The graph in the bottom is the curve of the appointed column. Click the column in the table to change the content of the graph. In general, the last result should be the average data of several measurements. Click <Add to List> to save the current result to the average table, which can be check in page [Result List]. It is recommended that one s ample should be t ested at least 3 times to get an average result. 61

42 e. Return to page [Measurement], relocate the sample and repeat a-d. f. All the added results are shown in graph in page [Result List]. Click <Average > to get the average results. 62

43 g. The averaged r esults ar e s hown in p age [Average Result], th e spectrum type i s same as the definition in page [Current Page] h. Save the l ast result by c hoosing the data type below E xport Operation. ( If i n page Current Result, this operation will save the current result) For Transmission Loss measurement The i nterface o f t ransmission measurement i s s ame as t he o ne o f ab sorption measurement except the page [Measurement]. The set up of the system should be accord with the picture in the two choices in page [Measurement]. The measurement involves two basic measurements with the two different terminations. One is with an anechoic or otherwise minimally reflecting termination, the pyramidal shaped section of sound absorbing material should be install in the end of the extension tube, and the one is with a blocked or open termination. It is recommended to use blocked termination to avoid the disturbing of background noise. Hint 1: The longer of test time it takes to measure in page Measurement, the smoother the curve becomes and the more precise the result is. Hint 2: If the external signal generator is adopted, it must be phonating in the whole time of measurement. 63

44 4.Test specimen with different diameter To get full-band results, the tubes with different inner diameter should be us ed together. Change the test tube and reset the information in. Repeat 1, 2, 3 and save the last result of each frequency band. In general, the chosen tube would be 100mm tube, 100mm tube with wide spacing and Small Tube(30mm, 16mm), or 60mm tube, 60mm tube with wide spacing and Small Tube(30mm, 16mm), reset the tube in <Setting> window according to the actual impedance tube used. The specimen should be cut as the tube cross section. 5.Data Combination Click <Data Combination> after finishing the test of specimen with different diameter. i. Click <Load> to c hoose t he r esult n eeded t o c ombine. The d ata w hich will be combined should accord with the title in front of <Load>, Or else, the combined result is wrong. In general, there are 4 results at most of different frequency range. in front of <Load> is t o c ontrol t he di splay of l oaded dat a and t he dat a n eeded t o combine; in front of <Combine> is to control the display of combined data. j. Click <Combine> to combine the chosen curves. The combined curve is the original test result. You can click <Smooth> to reduce the roughness of the curve. 64

45 Hint: th e combination s c omputational al gorithm o f abs orption r esult and t ransmission result is difference. Choose test mode in Setting windows before combination. k. Save the combined result by choosing the data type below Export Operation l. For sound absorption coefficient measurement, practical sound absorption coefficient and w eighted s ound absorption coefficient c an be c alculated by clicking <Rating> according to ISO 11654:1997. m. Click <Report> to fill in the information of martial and measurement, and all of them can be export to EXCEL as result report. Hint: If Original Data is chosen in Graph, and the frequency range is from 50Hz to 10000Hz, the data volume will exceed the upper limits of EXCEL and it will result in error. 65

46 6 Data Comparison Click <Data Comparison> to enter this window. Its function is to compare the saved test results. The different testing data can be loaded and shown in one figure. At most 10 groups can be compared in one time 66