2008 SPCR facility/equipment upgrades: hemi-anechoic chamber
Posted: Tue May 27, 2008 7:55 am
As suggested by Skirge01, I'm starting a discussion thread about the improvements and upgrades that will be financed in part by the funds contributed by the generous community of SPCR visitors.
Several new measurement tools were acquired over the last few weeks:
SpectraPLUS RTA software for the PC -- this $1000 package contains a complete SPL tool in its huge array of acoustic measurement features. Needs a high precision low noise mic.
Another B&K 2203 sound level meter with 1" mic and vibration meter kit. This was a lucky eBay purchase. It's always nice to have a backup, and I nabbed it for just $600. The SLM looks to be in excellent condition, its readings match the existing B&K 2203 SLM and the SpectraPLUS SLM within about 0.5 dB. The vibration meter attachment is really interesting. Have not had a chance to test it yet, but if it works well, it could help in the construction of the anechoic chamber -- and in vibration testing of HDDs.
Kanomax Anemomaster 6803 -- very high precision $700 anemometer kit accurate within 1% down to 40 ft/m; this is very low. The vane sensor is impressively low friction; just walking while holding it turns the vanes and gives a reading. It's the 3rd anemometer in the lab, and by far the most accurate. It was deemed necessary for more consistent fan airflow testing. You'll read about it in a new fan test methodology article that will come in a couple of weeks.
ACO Pacific 1" test mic kit -- This $2000 mic kit is the lowest priced precision mic with self noise at 10 dBA or below that I could find. The mic head has the same fitting as the B&K 1" mic head -- they are interchangeable. This mic head will be the reference to which all the others in the lab will be calibrated -- it is new, with its own individual response chart (flat to 8kHz, then within 0.5 dBA out to about 18 kHz; perfect for SPCR needs). It will be used with SpectraPLUS. No chance to do any serious work with it, but it clearly works and it's extremely quiet.
The anechoic chamber is still in the planning stages. One major change is location. I've decided after much consideration that building it in the garage will be more practical, and just as effective for noise isolation. Building a room in an existing room poses very tough technical challenges I don't want to face if I don't have to.
Photos and more to come later.
Several new measurement tools were acquired over the last few weeks:
SpectraPLUS RTA software for the PC -- this $1000 package contains a complete SPL tool in its huge array of acoustic measurement features. Needs a high precision low noise mic.
Another B&K 2203 sound level meter with 1" mic and vibration meter kit. This was a lucky eBay purchase. It's always nice to have a backup, and I nabbed it for just $600. The SLM looks to be in excellent condition, its readings match the existing B&K 2203 SLM and the SpectraPLUS SLM within about 0.5 dB. The vibration meter attachment is really interesting. Have not had a chance to test it yet, but if it works well, it could help in the construction of the anechoic chamber -- and in vibration testing of HDDs.
Kanomax Anemomaster 6803 -- very high precision $700 anemometer kit accurate within 1% down to 40 ft/m; this is very low. The vane sensor is impressively low friction; just walking while holding it turns the vanes and gives a reading. It's the 3rd anemometer in the lab, and by far the most accurate. It was deemed necessary for more consistent fan airflow testing. You'll read about it in a new fan test methodology article that will come in a couple of weeks.
ACO Pacific 1" test mic kit -- This $2000 mic kit is the lowest priced precision mic with self noise at 10 dBA or below that I could find. The mic head has the same fitting as the B&K 1" mic head -- they are interchangeable. This mic head will be the reference to which all the others in the lab will be calibrated -- it is new, with its own individual response chart (flat to 8kHz, then within 0.5 dBA out to about 18 kHz; perfect for SPCR needs). It will be used with SpectraPLUS. No chance to do any serious work with it, but it clearly works and it's extremely quiet.
The anechoic chamber is still in the planning stages. One major change is location. I've decided after much consideration that building it in the garage will be more practical, and just as effective for noise isolation. Building a room in an existing room poses very tough technical challenges I don't want to face if I don't have to.
Photos and more to come later.