[chbot] High Accuracy Thermometer

[Charles Manning]

What sort of accuracy are you trying to achieve?

The water + crushed ice method should give you better than 0.5 degrees. Better 
than 0.1 degrees if you use deionised water and a closed jar (to control the 
water vapour). 

For another reference use a medical thermometer (or better still an ovulation 
thermometer) They're accurate and cheap.

-- CHarles



On Tuesday 13 July 2010 12:55:22 Nathan Kennedy wrote:
> Ah, good point Charles, high accuracy is what I was meaning.
>
> I've compared the readings with other thermometers (aquarium thermometer,
> my baby daughter's bath water thermometer), and they all seem to be within
> a degree of each other.
>
> I was measuring the temperature of my wife's tropical fish tank. Both my
> probes measured 25.9, the bath thermometer measured 26.0, and the aquarium
> thermometer measured 26.7. I thought it would be good to compare with a
> known accurate thermometer to know which reading was the closest.
>
> Thanks again,
> Nathan.
>
>
> -----Original Message-----
> From: chchrobotics-bounces at lists.linuxnut.co.nz
> [mailto:chchrobotics-bounces at lists.linuxnut.co.nz] On Behalf Of Charles
> Manning
> Sent: Tuesday, 13 July 2010 12:33 p.m.
> To: Christchurch Robotics
> Subject: Re: [chbot] High Precision Thermometer
>
> High accuracy or high precision?
>
> A thermistor is about as precise as you'd ever need but won't be
> accurate without good references.
>
> Crushed ice and water give a pretty good 0deg C reference.
>
> On Tue, Jul 13, 2010 at 10:57 AM, Nathan Kennedy
>
> <nathan at kennedytechnology.com> wrote:
> > Good morning all,
> >
> >
> >
> > Does anyone in the group have access to a high precision thermometer? I
>
> have
>
> > built a couple of temperature probes and based the temperature
>
> calculations
>
> > on the datasheet specifications (and the results are consistant across
> > probes), but would like to compare against a high precision thermometer.
> >
> >
> >
> > Thanks,
> >
> > Nathan.
> >
> > http://kturl.com/blog
>
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