Cambridge dual gasanalysis gauge?

Seems there is at least a single engine and twin engine version of this instrument, and perhaps individually scale markings per engine type.

I found this entry in my copy of the RAAF Wartime index of aircraft instruments

RAAF ID G106/38 RAF ID 106A/38 Cambridge type DLA is a 24V twin Engine Gauge for Hudsons

RAAF ID G106A/50043 RAF ID —– Cambridge Type SIA is a 12 volt twin Engine Gauge for the Wirraway

There appears to be no RAF equivalent ID for the Wirraway version (I would have thought the Harvard I would be identical to the Wirraway instrumentation as both were direct NA-16 derivatives??.

I will try to scan a better photo of a Wirraway one if I can locate a good picture I no longer have any actual examples of the instruments myself.

regards

Mark Pilkington

Denys, Mark,

Is it possible that I can get a good photograph from the gauge that you found? Could be usefull for me in the future.

best regards,

Mathieu :rolleyes:

Denys,

found a cambridge fuel ratio meter today, and its looking for a good home, check your Private Messages for contact details of the owner.

regards

Mark Pilkington

Hei everyone,

As promised a photograph from the T 8W instrumentpanel with the cambridge gauge. This panel is from a T 8W in Luftwaffe service as you can see the repeatercompass, the Germans used 24 T 8W with the 1st and 3rd staffel from S.A.G. 126 at the same time that the British 320 sqn was equipped with 9 T 8W’s. As far as I know the T 8W was the only aircraft that was operational by both, the Germans and British at the same time.

Best regards,

Mathieu

Cambridge – was/is? the name of the UK manufacturer, more well known for scientific/electrical laboratory or test equipment rather than aero instrumentation

regards

Mark Pilkington

Thanks a lot for all your replies!!
I have a photograph from a fokker T 8W instrumentpanel but didn’t know which gauge it was on the photo, but now I know. as soon as my scanner is working again I´ll put it on this posting
Was Cambridge the name of this paricular gauge or from its manufacture?
Also nice to know if there were many type of aircraft equipped with this gauge.

best regards,

Mathieu

Cambridge Exhaust Gas Analyser

This instrument was built by an established Electrical instrumentation company in the UK rather than a mainstream aviation instrumentation company, the instrument works on a wheatstone bridge resistance measurement principle whereby a small sample of engine exhaust gas is injected into a gas analyser chamber in the engine compartment and changes the conductivity in an aluminium mesh chamber, the change in resistance compared to a standard arm in the “bridge” is measured on the indicating instrument, I assume it therefore measures unburnt fuel content? lean mixture etc (I cant recall the units of scale as I no longer have my examples,
Australian CAC Wirraways were fitted with such instruments in the front cockpit)

regards

Mark Pilkington

Hi Denys,
Send us an e-mail when you get a chance mate. Address is: [email]grigg_matt@yahoo.com[/email]

Cheers,
Matt

Try this site:
http://www.afn.org/~wjh/tsc/supra/afguage/airfuel.htm

Mathieu

I have been looking for such a gauge for a while for our Lockheed Hudson if you’re enquiring about one that looks like this which is a fuel-air ratiometer and is fed by the Cambridge gas analyser coil which is an accessory to the engine of course.

I don’t know but would assume they’re generic to the period and perhaps US aircraft or some such class??

hope this is of some help and if you’ve access to such I’d be keen to hear from you.