fv1609

is the gap in the white semi circle part of the answer if not why not a complete circle

Yes Wally the gap is important in order to read what is underneath.

Artillery control marking?

Simon

Nope its not that Simon.

Is it a hitching or coupling indicator?

Nope its not that Mike

as l under stand this you place flat with the red facing up to indicate one thing turn it over so the blue shows to

indicate another thing yes/no

Correct Wally

Does it indicate flow direction and temprature in pipework?

Another sensible one Tony but its not that.

To place on unmarked containers to indicate contents? Red Petrol, Blue Kerosene?

 

Alec

Sensible idea Alec but not that.

They are used to mark if meat is safe to eat or not; blue for good, red for bad.

 

Cheers,

Terry

Good idea Terry but not that

is this item only used by one branch of the services ie the navy

Yes Wally but not the navy.

Does it indicate a centre line

Nope not that Roy

If it has two sides then it is an object as opposed to a painted sign. This being the case is it flat?

Yes it is indeed flat.

Some sort of level indicator, perhaps?

 

Andy

Nope not that Andy

is it a form of telegraph indicator like that on a ship

Nope Wally no moving parts, but it is placed somewhere to indicate something depending which way up it is & where it is positioned.

or does it spin, red/blue used to discern when it's rotating? Maybe wind speed or engine rotation?

That's a novel idea but nope

Does red and blue represent forward and backward / fore and aft?

Nope not that Lauren

IS it used in direction finding as in artillary

Nope not that Wally.

NBC warning signs, blue safe, red danger?

Simon

Nope not that Simon.

blue friendly red enemy

A good one but not that Wally.

Hmm, alignment/coupling marks? Red to red, blue to blue etc?

 

Alec

Nope Alec not that. If it helps these particular ones were in use in the 1950s-90s although they may have been based on a wartime system but I don't know.

Assembly area?

 

Alec

Nope Alec not that.

Are the red and blue anything to do with hot and cold?

 

Andy

Nope not a temperature thing Andy

for want of a better discription is this a dial instrument that as you say is viewed one side at a time to give differant readings

Nope Wally not used in conjunction readings.

Boundary marker for safe areas?

Nope its not that Tony

Is it travelling very fast (one side is red-shifted) http://en.wikipedia.org/wiki/Redshift

Wow Lauren that's clever stuff, beyond me though. It's not that sort of phenomenon.

Pacman has a sore throat.

:rofl::rofl::rofl:

A symbol used on Stores to denote the type of storage required?

Richard I think we exhausted all those! Nope it's not that.