Category: Hardware
Product Number: LTM2985
Hello ADI,
I have trouble reading the values of two PT100 RTDs as cold junctions for two thermocouples. The RTDs have a shared RSense of 2 kΩ and are configured in 2-Wire-Mode. My schematic is very close to figure 12, “Shared 2-Wire RTD Example”, in the LTC2985 Datasheet (Rev. A) on pages 39 and 40. To illustrate my problem, I have copied the two pages and put my values in.
The data I get for the PT100 cold junctions are both approximately 2 Kelvins too high. I reviewed the schematic and the code intensively but found no error so far. Is it possible that this is a regular aberrance? I would expect the measuring system to be much more precise. Isn't it?
Kind regards,
Mario
