Floating hydrometer question

I picked up a floating hydrometer and I'm wodering if they are affected by
barometric pressure? When I float it in RO water it reads 1.004. Since I'm
located in Iowa, which is above sea level a bit, will this affect the
reading a bit?

As it is, I use 1.004 as a base reading and adjust accordingly.


Thanks,
Mark

"Mark Cooper" wrote in message
.. .
I picked up a floating hydrometer and I'm wodering if they are affected by
barometric pressure? When I float it in RO water it reads 1.004. Since I'm
located in Iowa, which is above sea level a bit, will this affect the
reading a bit?


Nope. A hydrometer measures the specific gravity of a liquid independently
of barometric pressure. However, hydrometers are effected by the
temperature of the liquid you are measuring.

You need to adjust for temperature.




As it is, I use 1.004 as a base reading and adjust accordingly.




Thanks,
Mark

Mark Cooper wrote:
I picked up a floating hydrometer and I'm wodering if they are affected by
barometric pressure? When I float it in RO water it reads 1.004. Since I'm
located in Iowa, which is above sea level a bit, will this affect the
reading a bit?

http://en.wikipedia.org/wiki/Elevator_paradox_(physics)

It shouldn't be affected suggesting that it is either miscalibrated or
that your RO water is rather "heavy." How about temperature?

-K

Kelsey Cummings wrote in
:

Mark Cooper wrote:
I picked up a floating hydrometer and I'm wodering if they are
affected by barometric pressure? When I float it in RO water it reads
1.004. Since I'm located in Iowa, which is above sea level a bit,
will this affect the reading a bit?

http://en.wikipedia.org/wiki/Elevator_paradox_(physics)

It shouldn't be affected suggesting that it is either miscalibrated or
that your RO water is rather "heavy." How about temperature?

-K


Cold water, right out of the holding tank.

Mark Cooper wrote:

Cold water, right out of the holding tank.

A hydrometer reads about 0.001 lower for every 10 degrees F rise in temperature.
If, for example, you would like to see a reading of 1.025 at 60 degrees, but
your tank is at 80 degrees, you expect to see 1.023.

George Patterson
All successes in conservation are temporary. All defeats are permanent.

Kelsey Cummings wrote:
Mark Cooper wrote:
I picked up a floating hydrometer and I'm wodering if they are affected by
barometric pressure? When I float it in RO water it reads 1.004. Since I'm
located in Iowa, which is above sea level a bit, will this affect the
reading a bit?

http://en.wikipedia.org/wiki/Elevator_paradox_(physics)

http://tinyurl.com/nelfm

That will work a bit better.

-K

George Patterson wrote in
news:VoiWg.1386$i84.84@trnddc01:

Mark Cooper wrote:

Cold water, right out of the holding tank.

A hydrometer reads about 0.001 lower for every 10 degrees F rise in
temperature. If, for example, you would like to see a reading of 1.025
at 60 degrees, but your tank is at 80 degrees, you expect to see
1.023.

George Patterson
All successes in conservation are temporary. All defeats are
permanent.

Thanks all!

Mark