I have Qty 2 of 731B, Both battery packs were NiCd and were dead when I received them. I built two packs with the largest amp-hour NiMH D cells that I cold find. I drove all day with the references to a cal lab two years ago. Even with the battery back up, the references required more than a day on the cal lab bench to settle.
cheers Brian Smith On Tue, Aug 6, 2019 at 11:30 AM Tom Knox <[email protected]> wrote: > An interesting side note, there are 9AH batteries with the exact same > dimensions as the 7AH. In addition Power-Sonic (and perhaps other > manufactures) have a DOT exemption allowing them to be shipped on all > aircraft which can save time and trouble when shipping the 732B for > calibration or other reasons. I think that the big concern affecting > calibration is if the unit actually powers down and the extra battery life > and DOT exemption can really help avoid the battery dying during shipping. > Cheers; > > Tom Knox > > 303-554-0307 > > [email protected] > > "Peace is not the absence of violence, but the presence of Justice" Both > MLK and Albert Einstein > > ________________________________ > From: volt-nuts <[email protected]> on behalf of Illya > Tsemenko <[email protected]> > Sent: Tuesday, August 6, 2019 9:35 AM > To: [email protected] <[email protected]> > Subject: Re: [volt-nuts] Fluke voltage standard > > Because any power cycle or temperature cycle expected to cause output > shift due to hysteresis and these standards designed to be always > powered on without any interruptions, otherwise uniform constant drift > characteristics cannot be guaranteed. IN CAL LED circuit monitors power > and thermistor value, so when your battery depleted below threshold, or > temperature outside of the normal window LED will be turned off. Fluke > recommends to perform recalibration after standard lost IN CAL LED > status. Typical battery life of 732B is ~3 days and that can be extended > once you have external chargers/+12V DC supply for backup power. > > This concept applies not just for 732 series standards, but for any > voltage standard which try to claim ppm annual stability. That also > includes 8.5-digit DMMs like 3458A and multi-function calibrators like > 5720A/5730A. Less stress changes in temperature/power - longer life for > instrument. Drift might be bit more, but it would be predicable once > characterized properly. > > On 8/6/2019 11:03 PM, Victor Silva via volt-nuts wrote: > > Can anyone explain why the Fluke Voltage standards, like 732B, which I > use > > as my primary standard, turn off the IN-CAL LED when they lose power > > (including battery)? I believe the same is true for the 732A, but I do > not > > have one so I'm not sure on that model. > > > > > > > > My 732B lost power during the hurricane in NC last year and the CAL LED > is > > off. I realize I can press the reset button to turn it on, but that > doesn't > > really make it in cal if it was out. > > > > > > > > Is the CAL LED really just an indicator to warn that the unit has lost > power > > or does the unit actually go out of spec after a power loss? > > > > I can see a scenario where there was a power loss then power came back, > > without that LED you could use the standard before it stabilized. > > > > But if you allow it to stabilize for some time, my question is will it > be in > > CAL still [but with the LED off]? > > > > > > > > Thanks, > > > > Victor Silva > > > > _______________________________________________ > > volt-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > > and follow the instructions there. > > > > > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
