DGS-10

Finding a Leak, Not Measuring It

This is worth understanding first, because it explains why this instrument gives no number.

A gas detector tells you the concentration where it’s standing. That’s what you want when the question is whether an atmosphere is safe.

It’s close to useless for finding a leak. Once you’re inside a gas cloud, the reading is high almost anywhere you put the sensor, and a high reading in five places doesn’t tell you which one is the source.

What finds a leak is the gradient. Concentration rises as you approach the source, and falls as you move away, and following that slope leads you to the leak. The DGS-10 is built to do exactly that, and nothing else.

How the Tick Rate Works

This is the technique, and it’s counterintuitive the first time.

Start by setting the red LED and the audible tick to the background gas level in the area. As the sensor moves into a higher concentration, the flashes and ticking speed up.

Then comes the part people miss. When the tick rate gets too fast to be useful, adjust it back down to background, and keep going. Then again. Each adjustment resets the scale, so the instrument stays sensitive to the next increase, rather than ticking flat out while you wander around.

So the adjustable tick rate isn’t a sensitivity setting to dial in once. It’s the working method, and it’s how you narrow down from a room to a joint.

The Gooseneck and the Tip Light

These are two practical features that matter more than they sound.

The gooseneck is 406 millimetres of flexible probe with a small sensor head. It reaches behind a unit, under a floor, into a duct or around the back of a manifold. A leak is rarely in a convenient place.

The sensor head has an LED built in, so the area the sensor is in is lit. On a job under a house or behind a boiler, that removes the juggling of a torch in one hand, a detector in the other, and a mirror somehow as well.

After use, the gooseneck wraps around the rubber sleeve on the body, which keeps it protected in a toolbox, rather than bent.

Gases It Responds To

Acetone, alcohol, ammonia, butane, gasoline, jet fuel, hydrogen sulphide, industrial solvents, methane, lacquer thinner, naphtha, propane and natural gas.

The sensor is solid state, and responds broadly to flammable gases and organic vapours, so the list is indicative rather than complete. It doesn’t identify which gas it has found, and it isn’t calibrated to report a concentration for any of them.

Two Things It Isn’t

Both are worth stating plainly, because getting either wrong has serious consequences.

It isn’t a hazardous area instrument. No ATEX, IECEx or intrinsic safety approval appears in its documentation. It’s a battery powered handheld tool for residential and commercial HVAC work, and it shouldn’t be taken into a classified area. For leak location in a Zone rated environment, a certified instrument is required.

It isn’t an atmospheric monitor. There are no alarm levels, no LEL reading, no oxygen measurement and no exposure logging. It can’t tell you whether a space is safe to enter, or whether someone has been overexposed. Confined space entry and personal monitoring need a portable gas detector built for the job.

Used for what it is, finding a leak in a plant room or a residential installation, it does that job well, and at low cost.

Where It’s Used

Residential and commercial heating installation and service. HVAC commissioning and fault finding. Checking that completed work is leak free. Gas appliance service. Plumbing and gas fitting. Building services maintenance.