You are a firefighter in a building filled with black, noxious smoke. Suddenly the floor collapses beneath you. Fear not. Help is at hand with equipment, called Naviseer, that can locate your exact location even in areas that global positioning systems (GPS) cannot reach.

Or you are a soldier on the front line. The heat is intense and you are carrying a lot of gear. Again, a device the size and weight of a modern mobile phone can measure exactly how long you can survive in such an environment.

Or, more mundanely, you are the boss of an industrial unit and you simply need to make sure that the level of gases in the atmosphere is within limits allowed by the authorities.

In all such cases, the company with the equipment to help you out will be Shawcity – which has just moved offices near the Military Academy at Shrivenham.

Shawcity, which now turns over £2.5m a year and employs 22 people, started life in Faringdon in 1974 when founders, husband-and-wife team David and Sheila Chapman, came up with the idea, way before its time, of supplying electronic devices for regulating the efficiency of industrial boilers – things that are now becoming commonplace even for domestic installations.

The business expanded into producing all kinds of health and safety equipment, in line with increasing Government legislation in that area.

Then, in 2008, the couple sold the business to Cambridge company Ionscience, manufacturer of an instrument called the Phocheck Tiger, now widely used by the military and by many industries.

The Phocheck Tiger is a Photo Ionization Detector (PID) used for detecting and measuring volatiles (‘chemicals’ to most of us) in the atmosphere.

Nowadays PIDs are essential work tools for measuring such things as lower explosive limits, ammonia and hazardous materials. They are also necessary in such fields as arson investigation, industrial hygiene and safety, indoor air quality, remedying environmental contamination and maintaining clean rooms.

Sadly, the 2008 sale of the company neatly coincided with the start of the economic downturn and Shawcity suddenly found itself in the front line of spending cuts as armed services looked for savings in their procurement costs and private sector companies also experienced a drop in orders.

Managing director Neil O’Regan, who joined Shawcity from Ironside in 2008, said: “We had to make five redundancies, bringing the employee count down from 18 to 13.”

Now, speaking from what you might call the recovery position, he added: “2011 was a solid year with turnover picking up well. That is why we have moved to new purpose-built offices. We simply outgrew the old space.”

But how much is the company dependent on public spending? Was I right in guessing the answer was “not too much” given that the company has picked up since the 2008 downturn?

Mr O’Regan said: “We get huge orders from time to time from the public sector, that is local authorities and the forces, but they are irregular.

“Our bread and butter is the PID. It links everything together here and is our regular business. And that business of course is driven by health and safety legislation.”

All the same, the company has about 50 core instruments on its books and each one of these has several derivatives. Mr O’Regan explained: “We usually give expert advice first, then hire out the piece of equipment that is right for the job.

“Then, say, a council employee tells the powers-that-be that there is a case for buying a particular device — and then, after the sale, we are still in a position to service it.

“We work very closely with all our customers. What makes us different is that we can help at all stages.”

And with more and more skills needed to operate equipment these days, the company can also provide training for customers; or it can provide skilled operators, whether the task be measuring noise, air quality, vibration, or gases in the atmosphere.

But to return to military uses of Shawcity’s equipment. Have we not all be reading for the last year or so that the military is chronically short of equipment, boots even, let alone hi-tech gear such as heat-stress measuring devices?

Mr O’Regan added: “Sadly it does sometimes take a fatality for a piece of equipment to be taken up.

“That indeed was the case with the heat-stress measurement equipment. Someone did indeed die in training before it was realised how important it was to use such equipment.”

And as for our firefighter falling through the floor in the smoking building, I asked why, if such equipment is available, we residents of Oxford keep having our bicycles stolen – and then find them lost forever. Surely a simple device would make that scenario a thing of the past?

Mr O’Regan said: “We are not in the consumer market, but I am sure a time is coming when that will be the case.

“I think it would always be too easy for a thief to simply remove the device and it is probably still too expensive.”