Using a meter other than a 3468A with HP-IL?

[Garth Wilson]

This may not be quite what you were looking for, but what moved me from TI to HP was the HP82169A HPIL-to-HPIB (IEEE-488) interface converter which opens you up to a nearly unlimited number of models of instrumentation you can connect to the 41. It is essentially transparent, making the individual pieces of equipment appear to be on the HPIL, except that you use manual addressing, for example:

Code:

137  22
138  SELECT        \ Get ready to talk to the HP3457A 6½-digit DMM again.  (22 is the bus address of the DMM.)
139  "ACV;R,5,.02" \ Tell it to get ready to measure AC voltage with a maximum of 5V input and give .02% (1mV) precision
140  OUTA          \                                                         (This sets the range and number of digits.)

If you have the 82164A (or FSI-164, almost the same thing but with a minimum of two RS-232 channels and a maximum of eight, not just one), you can cobble together things on the workbench that would be much smaller, lighter, and lower-power than a nice piece of equipment in a big case. It takes more effort though. The typical approach would be to use a microcontroller, and since the microcontroller's A/D input will probably be 8 or 10 bits from 0 to 5V, you'll use an op amp to scale the input from the millivolts put out by your sensor to the volts required by the A./D converter, and possibly offset it as well if necessary. The op amp's input offset error and other specifications will need to be up to the job of course.