Test and Measurement Forum

We have a requirement to test a bed of up to 60 thermostats to determine and record the temperature at which each opens. The maximum temperature range over which we would sample is from 110C - 160C, however any specific test would span only +/- 20C.

Our preferred accuracy/resolution is 0.1C, but we could tolerate somewhat less precision. The thermostats will be in an oven with a rise time of 1C/min., so the sampling rate can be very slow (perhaps 6sec.). The temperature input will be from a 1K ohm platinum RTD (or a thermocouple would be ok).

For the digital (continuity) inputs, we would prefer to scan a 6X10 row-column matrix, but could provide a lead from each thermostat, if necessary. Therefore, we need either 16 or 60 digital inputs and one analog input. Data storage could be anywhere from 7,000 to 15,000 records (temperature/channel/state).

Can you offer a suggestion for your best hardware configuration to accomplish these requirements? Also, I’d like to know, if there are any software choices, which is preferred.

Thanks, Gregg

Hi Gregg, thank you for your post.

A few questions regarding your setup?

1) Do you require the system to be remote or is having a PC connected at all times not a problem?
2) How long is your test running for?
3) You mention digital inputs and one analogue input, I assume the digital channels say if a thermostat is on or off, however what is the analogue input used for?
4) How often do you wish to sample your data?

Kind regards

Thanks for your response to my question. Sorry for my delay in responding; the forum was locked.

1. A PC can be dedicated to the tester.
2. The maximum test time would be ~ 45 mins.
3. The digital inputs would be a matrix to scan each thermostat in a test bed and report its condition (open/closed). The analog input would be a 1K ohm platinum RTD, allowing the precise temperature of each themostat opening to be recorded.
4. A sample rate of 6 secs. would be ideal, but it could be as slow as 1 min.

Thanks, Gregg

Hi Gregg,

Yeah the forums has been undergoing a facelift.


In terms of temperature the PT104 can take PT1000 sensors. Each PT104 would take 4 inputs, you can have 3 or 4 PT104s connected to your PC (more can be used however it will be very slow).

In terms of your digital inputs we can measure them as analogue voltages, we do not do any kind of logic analysis. The Picolog 10000 series (1012 or 1216 12 channels and 16 channels respectively) can measure 0 to 2.5V. You can have multiple units connected to one PC.

So you can have a mixture of PT104s and PL1000s connected to your PC recording in the same instance.

So the question really is how many temperatures are you looking to measure and how many of the digital inputs are you looking to measure?

Kind regards