My Ethanol Sensor never reads zero, is it broken?

The Ethanol Sensor, order code ETH-BTA, $109 will never give a zero reading because of the type of calibration used.

The minimum reading will fall in the following range, depending on the interface:

Unit
% 0.007 - 0.010
ppt 0.07 - 0.100
ppm 70 - 100

If your sensor does not read in this range when exposed to air see TIL 2858: Does my Ethanol Sensor need to warm up?.