Familiar with Bruel & Kjaer Sound Level Meter Type 2221?

[powersys]

manuale bruel & kjaer 2221

I've a Bruel & Kjaer Sound Level Meter (SLM) Type 2221 as shown in figure below. As my department bought this SLM almost 20 years ago, the user guide or manual for the SLM is lost. I tried requesting some technical specifications of the SLM from Bruel & Kjaer but so far I receive no reply from them. Therefore, I will be grateful and appreciate any help from those are familiar with this SLM or other SLMs. Kindly advise the following:

[1] If 'Peak' function is selected, what does it mean? What does 'Max. Hold' mean?

[2] What kind of signal or info provided by the 'AC output jack'?

Thank you very much

 

[FvM]

1) The general meaning of these terms in measurement technique seems self-explanatory in my opinion, in this case the exact instrument characteristic (e.g. time constants and rectifier behaviour) is specified in standards for noise emission measurements. They should be discussed also in the respective professional/scientific literature and manuals of similar professional instruments.

2) As the name suggests, it's an AC output for the amplified microphone signal, most likely modified by the gain setting and possibly a selected (A or C) "weigthing" filter. Connect an oscilloscope or audio spectrum analyzer and see.

 

[FvM]

Re: Familiar with Bruel & Kjaer Sound Level Meter Type 2

As a supplement, here's a manual of a today's integrating level meter from another vendor. You'll recognise some features also present at the B&K 2221.


And the successor from B&K https://www.bksv.com/doc/bp1924.pdf

 

[B&K]

Re: Familiar with Bruel & Kjaer Sound Level Meter Type 2

This model of sound level meter was first introduced in 1982, 28 years ago! A significant number are still in regular use and come through the calibration department here at B&K Denmark frequently.

I have placed a copy of the 2221 user manual here which I hope will be of help.

ftp://ftp.bksv.com/DeletedAfterOneDay/SLM 2221/

If over the course of the next 28 years you would like to consider a replacement then you may well find user manuals have been supersceeded by built-in instructions and help.
https://www.bksv.com/products/soundlevelmeters.aspx

Happy measuring.

 

[powersys]

Many thanks to FvM and B&K.

 

[EyadAcs]

Re: Familiar with Bruel & Kjaer Sound Level Meter Type 2

I've a Bruel & Kjaer Sound Level Meter (SLM) Type 2230. My department bought this SLM without a manual. It is being used with the 4155 mic.

I tried making some measurements indoors using the following settings:

- Detector 'RMS'
- Time Weighting 'Fast'
- Display 'Leq'
- Sound incidence 'Random'
- Ext. Filter 'Out'
- 'Operate'
- Freq. Weighting 'Lin'

But I'm having the following problems:

[1] The display symbol for overload/illegal control setting is permanently on screen. I have adjusted the FSD and then selected 'Reset' 'All' but the overload symbol persists. Are my settings incorrect? Is my reset method incorrect?

[2] The display level increases by approximately 10 dB with each incremental FSD selection I make. Why does this happen? How do I know which is the correct FSD setting to use for different measurements?

[3] When I select Freq. Weighting 'A' the level shown is 0.00 dB with the overload symbol still on display. However selecting any other Freq. Weighting options gives me a level. My conclusion is that the A-weighting has malfunctioned. But I think there's a possibility that correcting the overload symbol might make it work?

[4] What is the procedure for field calibration? I have a B&K Acoustical Calibrator Type 4231 94 dB SPL @ 1 kHz.

This SLM is older than I am so I'd really appreciate any help from those are familiar with this SLM.

I have used various SLMs in the past, but I'm really struggling without a manual. Does someone have a copy of the Type 2230 manual they wouldn't mind me having a peep at?

Thanks in advance

 

[FvM]

I guess, the nice guy from copenhagen would recommend factory service.