Total Error Measurement with USB-2416

[Alain Compaore]

I am looking for the equation to calculate the Total Error (measurement and temperature offset) under these conditions

DAQ = USB-2416

DAQ Expansion = AI-EXP32

Temperature  variation in the room from  20C and 35C

Measurement = 0.00164V

Range = ±0.078125 V

A/D data rate = 3750 S/s

[Fausto]

Hello @Alain Compaore.

You did not mention using thermocouples as your signal's sensor type, so we don't need to consider the thermocouple's specifications from the thermocouple manufacturer.

The analog input DC voltage measurement specifications are listed in Table 12 of the user's guide and the values are typical for the device at 25 °C. 

https://www.mccdaq.com/pdfs/manuals/USB-2416.pdf

(Note: The USB-2416 should be warmed up for 45 minutes after the initial power on.)

 

in_val = input voltage reading (V)

act_temp = environment temperature

Total error = [(in_val) x (0.035 %)] + [6 µV] + [(0.078125 V) x (0.0009 %)] + [(in_val) x (0.0006 %) x (act_temp - 25 °C)] + [(1 µV) x (act_temp - 25 °C)]

 

Given:

in_val = 0.00164 V

act_temp = 35 °C

Total error = [(0.00164 V) x (0.035 %)] + [6 µV] + [(0.078125 V) x (0.0009 %)] + [(0.00164 V) x (0.0006 %) x (35 °C - 25 °C)] + [(1 µV) x (35 °C - 25 °C)] =  0.000000574 + 0.000006 + 0.000000703125 + 0.0000000984 + 0.00001 = ±0.00001738 V

If you are concerned about the surrounding environment's temperature, then consider using a protective enclosure for the USB-2416.  

Regards,

Fausto