Hello all, is it possible to recalibrate these instruments. I have
come into possession of one that reads too low on minum temp and too
high on maximum temp. It is like the mercury needs to be pushed back
around the tube somehow to bring the max / min scales in line.

On 2009-11-02, Scott W wrote:
Hello all, is it possible to recalibrate these instruments. I have
come into possession of one that reads too low on minum temp and too
high on maximum temp. It is like the mercury needs to be pushed back
around the tube somehow to bring the max / min scales in line.

Maybe there's a bubble somewhere? I've had to do this with mine which is
just a relatively cheap one from a garden centre. What I did was firmly
grip it and swing it round a few times in an arc. I did say firmly grip
it
--
comp.john

On Nov 2, 11:57*pm, Scott W wrote:
Hello all, is it possible to recalibrate these instruments. I have
come into possession of one that reads too low on minum temp and too
high on maximum temp. It is like the mercury needs to be pushed back
around the tube somehow to bring the max / min scales in line.

If the scale is on a plastic backing separate from the tube the
easiest thing to do is to shift the tube relative to the scale if that
is possible.

Tudor Hughes, Warlingahm, surrey.

Tudor Hughes wrote:
On Nov 2, 11:57 pm, Scott W wrote:
Hello all, is it possible to recalibrate these instruments. I have
come into possession of one that reads too low on minum temp and too
high on maximum temp. It is like the mercury needs to be pushed back
around the tube somehow to bring the max / min scales in line.

If the scale is on a plastic backing separate from the tube the
easiest thing to do is to shift the tube relative to the scale if that
is possible.

.... as Tudor writes, it's usually the plastic scale that has slipped out
of position, or become warped in some fashion. You're not going to get a
high degree of precision with these units, BUT, they are still useful. I
find I can estimate to the nearest fifth of a degree (C), and checked
against some standard thermometers over the years, I've always found
them to be a useful 'back-up'. I keep a unit running in my screen to act
as a check against me mis-reading 5 or 10 degC.

Martin.



--
Martin Rowley
W: booty.org.uk
E:

On Tue, 3 Nov 2009 at 01:12:05, comp.john
wrote in uk.sci.weather :

On 2009-11-02, Scott W wrote:
Hello all, is it possible to recalibrate these instruments. I have
come into possession of one that reads too low on minum temp and too
high on maximum temp. It is like the mercury needs to be pushed back
around the tube somehow to bring the max / min scales in line.

Maybe there's a bubble somewhere? I've had to do this with mine which is
just a relatively cheap one from a garden centre. What I did was firmly
grip it and swing it round a few times in an arc. I did say firmly grip
it

Not to mention making sure you're well away from any obstacle...
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)

Paul Hyett wrote:
On Tue, 3 Nov 2009 at 01:12:05, comp.john
wrote in uk.sci.weather :

On 2009-11-02, Scott W wrote:
Hello all, is it possible to recalibrate these instruments. I have
come into possession of one that reads too low on minum temp and too
high on maximum temp. It is like the mercury needs to be pushed back
around the tube somehow to bring the max / min scales in line.

Maybe there's a bubble somewhere? I've had to do this with mine which is
just a relatively cheap one from a garden centre. What I did was firmly
grip it and swing it round a few times in an arc. I did say firmly grip
it

Not to mention making sure you're well away from any obstacle...

It's all in the wrist action you know ;-)

grin

--
Keith (Southend)
http://www.southendweather.net
e-mail: kreh at southendweather dot net