Farnell DM131 Multimeter Thermal Probe

[WaveyDipole]

Out of interest I did a little research on the on that PM2524. It seems that it uses a PM9248 temperature probe. See about halfway down this page:
http://www.amplifier.cd/Test_Equipme...er/pm2524.html

The PM9248 is neither a thermocouple nor a P-N junction sensor, but a 'resistance thermometer':
http://freeservicemanuals.info/en/se...ne/USERMANUAL/
There is plenty of information about these at Wikipedia and from what I understand, they appear to be somewhat different to thermistors:
https://www.bing.com/search?q=resist...16&FORM=CHROMN

The Philips PM9248 manual does not give away much, except to provide the thermal characteristics and Philips might have loosely used the term 'resistance thermometer' to mean a thermistor, but could it have referred to an RTD? There are various classes of these devices, but there do seem to be some RTDs on eBay for around 3 quid so I was wondering whether something like this would work?
http://www.ebay.co.uk/itm/3mm-Dia-Pr...cAAOSwCGVX-5EA

[MrBungle]

Rather interesting - thanks for the links and detail. At that price I think I'll grab one and see what happens. I've got a suitable DIN plug floating around somewhere already.

[karesz*]

Hi Chris,
I think a PT100 should work too, but I belive:you must corrigate its values (look up table) than these metallic sensor has some different temp characteristic as NiCd, the original. Btw; I can not find such NiCd res-tem characteristic on the NET...
Karl

[Bazz4CQJ]

The original resistance thermometers date back a very long way and consisted of metal, often platinum, wire-wound sensors, and hence the common standard ‘PT100’. These gave a near-linear response (so they were relatively easy to use even in pre-microchip times) and they are very accurate and stable. Thermistors came along later, and although they do change resistance, they do so in a non-linear way and present much higher resistance values than the wire-wound sensors and there are many different specs. I think it's true to say that thermistors occupy the cheap and cheerful end of the market compared with platinum resistance sensors.

[MrBungle]

Originally Posted by karesz*

I think a PT100 should work too, but I belive:you must corrigate its values (look up table) than these metallic sensor has some different temp characteristic as NiCd, the original. Btw; I can not find such NiCd res-tem characteristic on the NET...

Thanks for this. Much appreciated. I've ordered one. Let's see what happens. Will post back in a month when it gets here

[Boater Sam]

My DMM from Clarke came with a wire thermocouple, the meter on its own reads ambient temperature so that's the low reference bit I assume.
Not a bad meter for the money, does transistors, diodes, capacitors, temperature, dBs, 10A AC & DC, resistance, continuity, volts to 750 and its in a plastic shoe for rough handling. Had it years and its still accurate.

[karesz*]

Chris,
Teks P6430 Temp Probe for, ie, 475-DM44 has very similar specs, I thank it must be a same Resistance sensor, but it has an transistor-junction inside
Karl

[karesz*]

Chris,
I found yet full ramdonly some description & discussion over PM9249, a PT100 TempProbe for PM2522A. we can read too, that hes connector will be multifunctionally used...
Regards, Karl