Hart Scientific 1522 digital thermometer needs repair - Page 1
Forum section: electronics / repair

author: acbern
author_rank: Frequent Contributor
timestamp: April 28, 2016, 02:11:48 pm
content: I recently got a Hart Scientifiy (now Fluke) 1522 digital thermometer, which is not fully operating. First of, an SMD coil was flying arround in the case (core broke off from its support, and was only held by one of its two wires); easy fix, used some epoxy glue to reseat the core and soldered the broken-off wire.Secondly, the NiMh battery is missing. Does anybody know what type is used there (seems a three cell battery, from the pictures I have seen, but voltage unknown). The manual does not say anything and the original spare part is unobtainium.Thirdly, it needs calibration (it says so on its display). For this, one needs to enter a passcode which is shipped on a tag together with the meter. Of course, it did not come with my used meter. In such case, one is supposed to contact the factory. I have not done that yet, and being in Germany, am not sure the Netherland Fluke support will help, so before I contact them, maybe someone here knows just off of its head (if it is that eays, e.g. the HP 3458A DMM uses 3458).And finally, anybody knows the pinout of the 6-pin cardedge info-co connector? Precision resistors are needed to do the cal, should be easy with known pinout, and I would prefer to get some data, if there is (have not found anything), rather then measuring, so link or just info would be nice if someone has.

author: Vgkid
author_rank: Super Contributor
timestamp: April 28, 2016, 03:03:18 pm
content: Look up the hart 1506. I believe there is a connector pinout in that one.

author: acbern
author_rank: Frequent Contributor
timestamp: April 28, 2016, 04:16:56 pm
content: Thanks, but the 1506 uses a different connector. The 1522 uses the so called (and proprietary) Infocon (includes also digital interface for EEPROM), the 1566 uses a circular one.

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: April 28, 2016, 07:12:44 pm
content: I got my password from Fluke with no issues. I sent them an email including serial number and FW version.I can take som pics of my only connector later to get you an idea. I think there are connections for a serial eeprom, 4-wire resistance, and a way to tell the meter the type of sensor that is attached.I will also get the battery info.

author: acbern
author_rank: Frequent Contributor
timestamp: April 28, 2016, 09:26:29 pm
content: Thanks. If you could get data re. your battery, that would be great, my main concern at this time (size per cell, voltage per cel, probably 1.2V anywhow, and capacity).Contacting Fluke re. cal passwords seems to be the way to go, agrred.

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: April 28, 2016, 10:07:37 pm
content: The cells are standard AA size 1.2V Ni-MH batteries. The capacity is 2700mAhBTW, don't be tempted to order one of these cables from Digikeyhttps://www.digikey.com/product-detail/en/ftdi-future-technology-devices-international-ltd/TTL-232R-5V-AJ/768-1068-ND/2441357. I couldn't get it to work but the example cable in the manual worked fine. I am guessing the 5V levels were not enough.I have attached a few pictures in case anyone is interested. Yes, the black wire is not connected. The probe failed cal due to "unstable readings". I put it in a dry well calibrator and it was fine. Most likely bad connection at INFO-CON adapter.

author: acbern
author_rank: Frequent Contributor
timestamp: April 29, 2016, 01:09:19 pm
content: Great, that solves both the battery as well as the connection questions. Thanks!As seen on your pictures, it seems the 4 contacts from left to right are connected to the sensor wires, and the two right ones to the EEPROM, right? (not so clearly visible as some parts are a little dark).

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: April 29, 2016, 01:18:44 pm
content: The connections appear the same to me. I can trace out the two lines later if you like.Also, I was mistaken about a jumper. I think the sensor type is set in the EEPROM.

author: acbern
author_rank: Frequent Contributor
timestamp: April 29, 2016, 02:21:46 pm
content: Would be good. Just want to make sure the 4 sensor lines are not connected elsewher, and the EEPROM is not connected to the sensor in any way (no reason why it should, but anyway.) Batteries ordered.

author: acbern
author_rank: Frequent Contributor
timestamp: May 01, 2016, 11:17:33 am
content: And here are some teardown pictures: