Re: Coolant hydrometer

[zm@mhcnet.att.com (Zafer Mehmood [209])]

> 
> > 
> > WRT the "radiator coolant testers" (aka floating balls hydrometers)
> > available, at what coolant temperature should one measure the "goodness"
> > of the coolant? (at 20F, I have 4.5 balls floating [and yes, I mean
> > four and a half -- that fifth ball floats about 1/8th inch below the
> > other four, won't rise, won't sink...], at 200F I have two balls
> > floating, so which do I "trust"?) The packaging literature was sparse
> > at best.
> > 
> 
> Take a known quantity of antifreeze and mix it and see how the balls 
> react. In short, don't trust it.
> 
> Dennis [Minnesota/BN Highline]

I have to agree with Dennis. I have also not had good experience with the
floating ball hydrometers. I have been using one made by Prestone for the
last several years that has a large red pointer in it; no floating balls.
This one is rugged and gives consistent readings. I tend to trust
it although I have not calibrated it against a known standard. The pointer
just indicates the concentration and freeze protection level (in degrees C
and F) against a dial printed on its body. Costs less than $5.


-----------------------------------------------------------------
Zafer Mehmood				   AT&T Bell Laboratories
zm@mhcnet.att.com			   Murray Hill, NJ