Calibration of exhaust gas analysers - anyone know anything?

Calibration of exhaust gas analysers - anyone know anything?

Author
Discussion

zcacogp

Original Poster:

11,239 posts

251 months

Thursday 29th April 2010
quotequote all
Chaps,

Quickie.

A friend bought a Crypton 267 exhaust gas analyser off eBay, for some work we will be doing together. Snag is that it reads VERY low on CO. (HC is fine, CO is way, way off, by a factor of 10 or so when compared with another machine.)

We know it needs to have the filters changed, but does anyone know anything about calibration of these machines (or exhaust gas anlysers in general)? There was a manual with it, but it wasn't very helpful on the topic of calibration and everyone in the trade seems to have their calibration done by an external company.

We have another machine (on loan) we can use as a reference point, but how do you set about calibrating this machine? We don't need it to be precisely accurate (i.e. not to MOT standards), and we only paid £80 for the machine so don't now want to be spending large sums on having it calibrated professionally to super-accurate standards.

All suggestions and help welcomed. Thanks.


Oli.

nelly1

5,637 posts

238 months

Thursday 29th April 2010
quotequote all
We used to use Horiba 4-gas analyzers and to calibrate these you used a can of reference gas - 5% CO IIRC.

You purged the unit, fed in the gas and adjusted the span until it read correctly.

The nearest I can find with a quick Google search is this... - ref. gas at the bottom of the page.

zcacogp

Original Poster:

11,239 posts

251 months

Friday 30th April 2010
quotequote all
Nelly,

That's helpful, thanks.

Do you happen to know anything about how to actually calibrate the unit in question? The process (compare with a reference sample of known composition) is great, but do you happen to know what you do to calibrate the machine? (Twiddle screws, take the cover off and move sliders, replace reference resistors in the circuitry ... what?!)


Oli.

nelly1

5,637 posts

238 months

Friday 30th April 2010
quotequote all
On our unit, there was a 'Span' potentiometer next to the gas inlet tube.

Can't help with your unit I'm afraid - why not try E-mailing the manufacturer?

zcacogp

Original Poster:

11,239 posts

251 months

Friday 30th April 2010
quotequote all
nelly1 said:
Can't help with your unit I'm afraid - why not try E-mailing the manufacturer?
That's a good idea - thanks!

(Not sure why I didn't think of it myself!)

Will keep you posted.


Oli.

AhmadReza

1 posts

115 months

Sunday 19th April 2015
quotequote all
Hello all
i have a Horiba MEXA-574GE
While i trying to calibrate o2 and i set atmosphere on 20.09% and press set a Exclamation point show on top let of screen and nothing happened.

anyone able to help me please...