humidity sensor problem

[CAI_Support]

During testing our new board, we noticed couple of our Honeywell humidity sensors not reading stable, even Fluke meter reading is very stable the humidity sensor output.
 
We then hookup digital scope to check out the humidity sensor output. That was a surprise. Despite the very stable reading by Fluke Digital voltmeter, scope showed the humidity sensor output with 1V peak to peak jumping and at 5KHz period not regular triangle noises.
 
We have ordered new sensor to make sure the problem is bad sensors.

 

[CAI_Support]

We tested with new sensor, it is indeed the sensor problem.  With new sensor, it is very stable.
Actually we knew it would be a bad sensor, since with resistors dividing 5V on the humidity sensor terminal, the reading is very stable.