Can AMUX-64T for thermocouple be connect to DAQ 12 bit?

[nattapol_stp@chula.com]

I'm using AMUX-64T for thermocouple type K. My application is connection the AMUX-64T to DAQ 12 bit (AT-MIO-16E-10, 100 kS/s, 12 bit, 16 Analog Inputs; NI6020E)? I would like to know how much this is effect on any temperature data recieved from my applicaton. If yes, how much error do you think? I should change to DAQ 16 bit whether, or not.

[JoshuaP]

The AMUX-64T can connect to just about any of National Instruments devices, because it is just a multiplexer and it is not performing any signal conditional or ADC.

Using a 12 bit board versus a 16 bit board will only affect your code width (CW = Range/(Gain * 2^Resolution)) and some boards have different gain settings.

For example if you have your device set up for bipolar (+-10V) and you gain set to 100 (this is set by setting your maximum and minimum voltage to +-0.1V) then your code width would be 49uV for a 12-bit device and 3uV for a 16-bit daq device.

But if you forget to change you gain or are using a device that does not have a gain setting of 100 your code width changes to 4.88mV for 12-bit and 0.305mV for a 16-bit device. Code width is the
minimum change the daq device can detect.

Normally if you are using the correct range and gain settings for your device you will be ok with a 12-bit device. Go to http://www.ni.com/advisor/accuracy/ if you want to see how the range, gain, and daq device configuration affects your measurement.

I hope this helps solve you question.

Joshua