I'm trying to calibrate my temperature sensors, but their values are so much off that I'm starting to wonder. I have sensors connected to an Aquaero 6xt, an old Aquaero 5 XT converted to LT and set as slave (udated firmware) and 3 different MPS's (neither of my Aquastreams read the external temperature). They all show values around 1-2C off what they should be showing. I'm using a bowl filled with ice (crusched and cubes) checking with a volt meter with temperature sensor (cheap model) and an ordinary in/out termometer both showing temp to be just about 0.5C too high). The bowl of water should be very close to zero, but I'll set it at 0,5C since it probably isn't exactly zero, and it hasn't started freezing. I use 3 different type of sensors. A Bitspower water termometer, some termometer with a plastic tingy around the resistor and 2 types (length, but resistors are different so that probably adjusts the reading) of flat resistor. All of them shows too high readings, from just under 1C to 2C. Has anyone else done something like this, and if so how much off where the readings? Correcting the values isn't a problem.

I'l have all the sensor take a dip in the iced water, guess at 0.5C and use the one closest to the average sensor readings as refference, adjusting the rest to match that sensor, then I'll check the readings at 20C, 30C, 40C and 50C to check the individual changes, using the refference sensor to adjust all the others at 30C as I guess that's closest to the average tems the system will have.