eliwell probe

[Eric the King]

I bought a batch of Ptc probes lately and after a number of days a number of them went out of calibration, has anybody got any idea what type of probe is used for the ID961 and ID974 PTC 100 or 1000? the batch I got were marked with an eliwell product colde on the cable of the probe but the all eliwell specify is a PTC probe. With this batch I purchased NTC aswell which seem to be fine. :cool:

[coolhibby1875]

the controllers can be configured to take either ptc or ntc!

[Eric the King]

Thanks for your reply, does the controller use a PTC 1000 or PTC 100 or PTC????

[NoNickName]

Simply PTC or NTC. The exact curve and range of resistor depends on the manufacturer.

[monkey spanners]

Thanks for your reply, does the controller use a PTC 1000 or PTC 100 or PTC????

Like NNN said, PTC but you can use NTC after altering the paramiters.

[toprunner]

Simply PTC or NTC. The exact curve and range of resistor depends on the manufacturer.

A curve for PTC ?? A PT1000 has 1000 ohms at 0 degree C and a PT100 has 100 ohm. It has a linear function from that point... maybe you can call that a curve

[NoNickName]

No, toprunner. The curve is not linear, and a general PTC (not a PTC100 or PTC1000) as much as a NTC may have any sort of value at 0°C or 25°C.
For example http://www.thermistor.com/references/curves_z-y-t-w.pdf you can find the characteristics of four different type of NTC curve z, y, t, and w. They are all called NTC, and none of them is the same.

You say that PTC100 and PTC1000 have a linear behaviour. What is the slope of the line? In other words, what is their R/T characteristic?