|3421: any tips on calibrating?|
Message #1 Posted by Vieira, Luiz C. (Brazil) on 23 July 2010, 11:03 p.m.
after a while waiting (some years...) I got my 3421, at last! My friend that had it actually took good care of it and had some personal issues (it took him about seven years to send me the unit... no problem, I can handle it once knowing we are dealing with friendly human beings that may surely have their reasons and circumstances), but anyway I finally have my own 3421!
These 'beasts' are timeless...
Before trying anything, I opened it and saw a 6.3V/2,4Ah sealed lead-acid battery. I also noticed that it came with a multiplexer/actuator assembly board. Needless to say the battery was dead: 1.8Vcc. I did not even try to charge it; the poor thing has already been sent to a proper recycle container, only for batteries (I do my part...). Then I measured the small battery that keeps RAM data and found 3Vcc! Amazing! That one was alive.
Before plugging it into the AC line (I found the mains supply voltage selection quickly), I replaced the lead-acid battery for another (taken from a 9114 battery pack) and the 3421 reacted with a small 'click' from a relay, I guess. I tried the POWER switch and it woke up with ERROR 0 (no RAM data). After plugging it into the AC line, the lead-acid battery voltage raised from plain 6.12Vcc to 7.01Vcc: the power supply seems OK.
I plugged it to an HP41 with MLDL2000 previously loaded with the X-IO and Data Acquisition ROM, and I tried some HPIL commands. The 3421 responded to all acceptable commands as expected, and generated some error messages, also as expected. I also performed the fastest measuring test described in the first pages of the manual: shorting the resistance input terminals and turn the unit ON. Both errors 0 and 7 (shortened input) showed up in the display. INSTAT returned a number to the X-register and set related flags.
Because I never had any HPIL measuring device before, I am still 'trying it out' with a lot of reasonable care. I will take some specific time this weekend to read some material about it: user manual, HP41 Data Acquisition ROM manual and four application notes related to calibration. The 254-page manual will give me the basics, I hope, along with the HP41 data acquisition ROM manual, but if there is something else I should know about, I'd appreciate any info/advise you can give me.
I remember seeing some posts about the 3421 at this very forum many years ago, but back then I neither have my HPIL, nor many stuff I have now (9114 disk driver, MLDL2000, Clonix/NoVRAM, documentation, knowledge basis... thanks to many of you, guys!), so I just read those messages briefly. I am now collecting many of them and I'll read them prior to go ahead.
I am positive it will take me some time, but hey! Better now then never. This is my first HPIL measuring device, I really want to go ahead using it accordingly.
Thanks a lot, from a 3421 'newbie'.
Edited: 23 July 2010, 11:22 p.m.