Temperature data recorder

Good day!

Can anyone enlighten me on designing a temperature data recorder?

what type of connectors are used on the recorder if it is spose to accept both J and K type thermocouples?

for a 10 channels temperature data recorder, does it have 10 cold junction compensation circuits and 10 adc chips in it?

thank you!

I would have your 10 thermocouples going into 10 pairs of terminal blocks (no special metal needed), then have 5 differential multiplexers feeding these signals into the cold junction temperature compensation circuit then out of this into a single differential ADC. The ADC is going to be the expensive bit, so multiplexing your signal into a single ADC will be simplest and cheapest way of doing it.


Alternatively, if your temperature is not going above 125 degC, use a silicon chip solution or thermistor in a resistive divider then you dont have to worry about cold junction temperature comp

thanks a lot for your reply.

multiplexer:
is that what is usually used in a multiple channel data logger? do they use multiplexer in their logger? can you recommend a multiplexer that i can use?

And for cold junction compensation:
I am planning to use AD594 for type J and 595 for type k, but how does my data logger know what type of thermocouple is connected to a particular channel before determining which chip (594 or 595) to send the signal to?

thanks again!