old ohmmeter repair/rebuild - need help from German readers - Page 1
Forum section: electronics / repair

author: Prime73
author_rank: Regular Contributor
timestamp: December 21, 2014, 04:46:12 am
content: I've came across this german made device which I think is an ohmmetter (see pictures below). I plan to make an attempt rebuilding and restoring it to its "former glory", unfortunately I don't speak German. I would really appreciate if someone could translate the manual from the back side of the device. Maybe someone knows what this device is and has any extra info, schematics, etc?Here is the text:Gleichstrommessung.A) Mit eingebauter BatterieX-Widerstand anschließen, Meßbereich 10 stöpseln, Taste drückenAusschlag links - Skalenscheibe recht drehenAusschlag rechts - Skalenscheibe links drehenMeßbereich ändern bis Nullstellung erreichtAbgelesenen Wert mit Meßbereichfaktor multiplizierenB) Mit 60 Volt AnodenbetterieMeßbereich 1000 stöpseln, Klappdeckel öffnen, eingebaute Batterie gegen Anodenbetterie austauschenWechselstrommessungZusatzkasten und Kopfhörer anstecken, Tonminimum einstellen wie bei A)Betterieersatz.Klappdeckel öffnen, Anschlußlaschen nach Skizze biegen und festziehen.

author: Maxlor
author_rank: Frequent Contributor
timestamp: December 21, 2014, 05:03:15 am
content: QuoteHope this helps, the german text is rather brief and not terribly clear.

author: RobertoLG
author_rank: Frequent Contributor
timestamp: December 21, 2014, 05:09:21 am
content: yep, seems correct, nice oldie

author: babysitter
author_rank: Frequent Contributor
timestamp: December 21, 2014, 12:09:50 pm
content: About what it is: It looks very,very Wheatstone-Bridgey to me.That means the potentiometer is part of such a bridge and the device under test also, you turn the potentiometer until the bridge is balanced, resulting in a zero reading on the meter.Case and text style make me considering Hartmann & Braun as primary suspected manufacturer, Siemens as secondary. Look at relevant websites if you can find a picture.You can supply a external voltage to the battery clips for testing.First, power it on and see if you can get the meter to hit both limits, should be very easy.Keep testing times short - test currents might be high.Switch off if the meter hits the edge, turn the poti "cold" and measure again.

author: Prime73
author_rank: Regular Contributor
timestamp: December 21, 2014, 11:58:04 pm
content: thank you all for the info. Are there any diy techniques to restore these aluminium plates with instructions? What process was used to print the text on aluminium in the first place?

author: babysitter
author_rank: Frequent Contributor
timestamp: December 22, 2014, 11:24:04 am
content: Personally, I would leave the plate exactly like it is in this case. If you real want to pop the rivets and install your own personal localized plate, drill or screw them out, and get a motor-maker make you a new one. But really, dont do it.Any success with testing yet?

author: babysitter
author_rank: Frequent Contributor
timestamp: December 24, 2014, 03:03:30 pm
content: I found a lead which one you might have:http://www.historische-messtechnik.de/passive-messgeraete/widerstand/kleine-messbruecken/ms-ia-86.php