- Voltage only, no current unless you had a special current adapter
- Neutral-ground voltage, waveform capture, and high frequency transients
- A jumper configured input system that you could actually, if you were not careful, short out the monitored voltage
- An interesting and often useful high frequency noise detector (RMS level only, no frequency component) that I’ve never seen replicated. Was great for sniffing out Simplex clock correction signals.
- Heavy as a beast (I lugged one overseas to Indonesia at one point)
- Somewhat delicate, with a mother board, processing board, printer, and keypad / led indicators
I’d receive 4-5 FedEx boxes a week with these (usually folded and flattened) which I would dutifully reroll in order to review and store. I had an 8′ table cleared to roll the tapes out; and designed in my head (but never realized) a tape reader with motors and push buttons to allow rapid scrolling and re-rolling this data. Interesting data was photocopied, and then physically cut out and pasted into little boxes that I had constructed in my report templates ( first Wordstar, pre-MS-Word). As we say, the good old days. Eventually, affordable scanner tech came along which made things only slightly easier.
And because I am feeling particularly nostalgic, and happened to have binders full of old reports at hand, here’s a sample page from a BMI-4800 report, circa 1995. Lot of love went into these reports…
Notice the report dated Feb 1995, and the data graphs dated Feb 1994. The BMI-4800 would replace that little BMI logo with an (Uncalibrated Data) message if the unit was out of cal, so it was pretty common for the field service group to set the date back a year to keep the output data looking fresh….I forgot about that until just now.
Somewhere along the line I bought a case of thermal paper; I’ve had these three lonely rolls kicking around in a file cabinet for nearly 20 years. I put them up on ebay with a $1 minimum for the lot, and nary a sniff. Time to let them go…..