ACS711 and ambient temperature

After reading the datasheet for the ACS711EX chip, I am left with the impression that varying ambient temperature may affect the readings of current flow. Where I want to use the current sensor would have an ambient range of -5c to +37c. That is based on uncontrolled outside temperature in north Florida. For other locations it would be different. The current sensor will not be exposed to rain/snow, but will operate in ambient temp/humidity.

Do I need an ambient temperature sensor to adjust the data being read to get consistent numbers ?

As far as I can tell, Pololu offers one temperature sensor, the MLX90614, but that is intended for measuring temperature of an object (and may be overkill for my needs). Would a thermistor be more appropriate ?

I know that the 32u4 has a temperature sensor onboard, but that is for chip temp, and may not correlate well to ambient.


Looking around for temperature sensor solutions, I came across the DHT11, DHT22, AM2302, RHT03 series. My first thought was the DHT11 would cover my needs, until I realized that it has a 0c floor. The DHT22 (and various similar devices) will report below 0c.

I think you don’t need to worry about temperature effects. If you look at page 10 of the ACS711 data sheet, the worst case error for a randomly chosen device, over the range of -40 to 125 degrees Celsius, is 5% of full scale. For a typical device, the error is less than 1% of full scale over the same temperature range.

You can always calibrate an individual device for better accuracy.