Products > Test Equipment
Princeton Applied Research 160 Boxcar Integrator
wishboneash:
Well, GAS has become my way of life; a late entrant to the TEA society. Does anyone here have any info on this beautiful looking piece of equipment - the PAR 160 boxcar integrator? Those 10 turn potentiometers... ah, so cool! I have been using lock-in amplifiers for a while now and seeing this available, I decided I must have it as it complements the lock-in amp in some ways. The only problem, I can't find any manuals online, user or service. I did get a manual for the PAR 162 which is a modular system, but this one is a completely integrated single channel unit.
No magic smoke when turned on, internal DC voltages all look good. Found one burnt out bulb which I am going to replace. Contacted Ameteksi who now own PAR, waiting for a response. If there are any boxcar integrator fanatics familiar with this unit, I would love to hear from you. Even better if you have access to any manuals that I could copy and return. Thanks.
Sam
wishboneash:
I put a video demoing some features of this unit. Excuse my kludgy editing/unrehearsed narration, but hopefully you get the gist of this amazing piece of instrumentation after watching some of the experiments I conducted. I can think of many uses for it already without having to resort to using a fancy digital storage oscilloscope.
Kleinstein:
The old instruments got pretty much replaced with digital methods. Many DSOs offer waveform averaging that das essentilly the boxcar integration for different delays in one run. Modern digital lock-in amplifiers may also offer this function that is somewhat related. Compared to the DSO they offer a better dynamic range (e.g. 18 bit instead of 8 bit ADC), but usually lower BW.
maxwell3e10:
Thanks for the video. Actually I was looking at boxcar integrators recently. SRS still makes one and there are probably similar more specialized instruments as well. Digital oscilloscopes can do waveform averaging but surprisingly inefficiently, recording only 1/10th of the waveforms, roughly speaking. It seems that it would be relatively easy just to build such integrator with CMOS switches. Found the specifications for PAR 160 online. It's actually more versatile than current SRS model 250. The gate time goes down to 10 nsec, so it would not be totally trivial to replicate with CMOS. It's cool how it can reconstruct a MHz waveform on a chart recorder. I feel people were generally smarter before computers came along :)
maxwell3e10:
It's interesting that Princeton Applied Research came up with a lock-in amplifier and a boxcar integrator at about the same time. Lock-in amplifiers are still widely used, but boxcar integrators faded from use. There were some averaging digital oscilloscopes or signal averagers made by Nicolet and perhaps others, but the most modern instrument along these lines seems to be FastFlight-2, which is long discontinued, as discussed here: https://www.eevblog.com/forum/testgear/4-gss-oscilloscope-with-averaging-and-very-fast-retrigger/.
But signal averaging is such a basic task. It would be relatively easy to have an ADC with a circular memory buffer that simply adds data on each pass, without needing a large system throughput. I am just wondering why such instrument optimized for averaging doesn't exist.
Navigation
[0] Message Index
[#] Next page
Go to full version