I hear that thermocouples, especially type K, got really low output voltage ( 41µV/°C. )
Someone told me that if I had 16 bit DAQ device I would need a range from - 1 V to 1V to measure 1 °C.
So the problem is if my DAQ usb device would record the temperature changes without any signal amplifier ?
I got in mind two devices :
I. USB 2416 24 bit Voltage Mode: ±20 V, ±10 V, ±5 V, ±2.5 V, ±1.25 V, ±0.625 V, ±0.3125 V, ±0.15625 V, ±0.078125 V
II. NI USB-6218 16 bit Input range : ±10 V, ±5 V, ±1 V, ±0.2 V
According to the mentioned statement, I should be fine with both but I need to know for sure because it's not a cheap ride.
BTW Does differential measurement have anything to do with the "sensitivity" level apart from noise elimination ?
Ok so it seems that I'm forced to use signal amplifier so I'd better start looking for wires, connecting amps with my DAQ device. Thanks for answers.