What causes Hydrometers to Un-Calibrate?

Porch Dweller · 07-13-2014, 09:25 PM

I've noticed that mine stay accurate for around six months or so, then need the battery changed. So every six months I change the battery and re-calibrate them.

RWhisenand · 07-13-2014, 09:46 PM

If you have an electronic hygrometer it works by reading the electrical resistance across a medium such as lithium chloride. As the batteries begin to degrade, the slight decrease in voltage will effect the resistance across the lithium chloride causing a false reading. By switching to lithium ion batteries you will reduce this need for calibration but not eliminate it altogether.

How this helped, BtW I spent 17 years in the field as an instrumentation tech, prior to moving into systems integration, and now management. I dig this stuff.

07-13-2014, 09:25 PM	#1
Porch Dweller Life is for living Join Date: Oct 2012 First Name: James Location: Mississippi Gulf Coast Posts: 8,783 Trading: (24)	Re: What causes Hydrometers to Un-Calibrate? I've noticed that mine stay accurate for around six months or so, then need the battery changed. So every six months I change the battery and re-calibrate them. __________________ A 1911 in the hand is faster than 911 on the phone

07-13-2014, 09:46 PM	#2
RWhisenand Feeling at Home Join Date: Aug 2011 First Name: Rob Location: Nevada Posts: 798 Trading: (7)	Re: What causes Hydrometers to Un-Calibrate? If you have an electronic hygrometer it works by reading the electrical resistance across a medium such as lithium chloride. As the batteries begin to degrade, the slight decrease in voltage will effect the resistance across the lithium chloride causing a false reading. By switching to lithium ion batteries you will reduce this need for calibration but not eliminate it altogether. How this helped, BtW I spent 17 years in the field as an instrumentation tech, prior to moving into systems integration, and now management. I dig this stuff. __________________ No function well beer without.