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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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Thread Tools |
4th Oct 2017, 6:23 pm | #1 |
Hexode
Join Date: Mar 2008
Location: Wakefield, West Yorkshire, UK.
Posts: 438
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Ohmeter 18B
I have a megger and continuity tester, "Ohmeter No. 18B".
I've got the instructions somewhere, but can't find them. Okay, I'm wanting to make sure that the test set is giving a correct reading for continuity. I think this is the "LOOP" position. I'm feeding 9v DC to the set. I have set one switch to "LOOP" (under "TEST FUNCTION") and the other (under RHEOSTAT VALUE") to divide by 10 (On the LOOP position). I've connected a 1 Ohm resistor across "LINE" and "RETURN". I get a balance when I set the rheostat to setting - 0018. Translated that says the resistor is 1.8 Ohms. Now, since the (brand new) resistor has a tolerance of 5% I should not get a reading above 1.05 Ohms. I've checked with another type of 1 Ohm resistor and I get a similar result. So, can anyone suggest why I'm getting a result that is far too high? Thanks. |
4th Oct 2017, 8:38 pm | #2 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,528
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Re: Ohmeter 18B
Lead resistance? Meter test leads usually run at about half an ohm or so.
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4th Oct 2017, 9:45 pm | #3 |
Hexode
Join Date: Mar 2008
Location: Wakefield, West Yorkshire, UK.
Posts: 438
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Re: Ohmeter 18B
The test resistor is connected directly across the terminals. No leads to the resistor. Will have to try to find the instructions to see if I'm doing things right.
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11th Oct 2017, 5:38 pm | #4 |
Tetrode
Join Date: Sep 2009
Location: Loughborough, Leicestershire, UK.
Posts: 94
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Re: Ohmeter 18B
We may have some of these in the workshop, I will have a look at the weekend to see if any of them have documentation.
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