testo 310 II

What It Measures and What It Works Out

The testo 310 II has two measurement cells, one for oxygen and one for carbon monoxide, plus a temperature sensor built into the flue gas probe.

From those, it works out the rest. Carbon dioxide, combustion efficiency and flue gas loss are calculated. Ambient temperature, ambient carbon monoxide, draught and pressure are measured alongside, and all of it can be shown at the same time on the display.

That’s the full set of parameters a boiler commissioning or service visit needs, which is the point of the instrument. It isn’t trying to be an industrial emissions analyser.

Draught, and Why It’s on the Instrument

Draught is the measurement most often skipped, and it explains more faults than any other reading here.

Technically, it’s a differential pressure measurement. A temperature difference between two areas creates a flow to balance it, and in a flue gas system, that pressure difference is what carries combustion products up the chimney. It’s measured between the flue gas and the ambient air, at the measurement point in the core of the flue gas flow. Boilers working at low pressure depend on it to move flue gases safely.

Getting it wrong causes a chain of problems, not a single fault. If draught is permanently too low, combustion is starved of oxygen. That produces soot and carbon monoxide, and lowers the efficiency of the system. So a boiler burning dirty and running expensively is often a draught problem rather than a burner problem, and measuring it tells you which.

The testo 310 II measures draught from -20 to +20 hPa, with a resolution of 0.01 hPa.

Ambient Carbon Monoxide Is a Separate Check

The ambient carbon monoxide menu measures the air in the plant room, rather than the gas in the flue, and it answers a different question.

Carbon monoxide is colourless, odourless and tasteless, produced by incomplete combustion of fuels containing carbon. Once in the bloodstream, it binds to haemoglobin and stops oxygen being carried. A leaking appliance in an occupied space is dangerous well before anyone notices anything.

Checking the flue tells you the appliance is burning correctly. Checking the room tells you whether what it’s producing is staying in the flue.

Designed for Easy Use

Small design decisions decide whether an instrument is pleasant to work with, and this one has several.

Magnets on the back of the housing hold it to a metal surface such as the burner, so a technician can take a reading without holding the instrument. Sensor zeroing takes 30 seconds. The rechargeable 1500 mAh lithium battery runs for more than eight hours, so it lasts a working day, and it charges over USB. The probe filter is quick to change and the condensate trap empties quickly, which matters, because they’re the two things that need attention most often.

At about 660 grams with the probe, it’s robust and light enough for daily use, even in rough and dirty surroundings.

App Connection

Bluetooth connects the instrument to the testo Smart App, which does three useful things.

It configures the 7 line display, so the parameters you care about are the ones shown. It adds simultaneous measurements the instrument doesn’t take on its own, such as gas flow pressure and flow and return temperature. And it documents the result, sending it digitally, with customer data managed in the app rather than copied from a screen into a notebook and then into a report.

That last one removes the step where errors creep in, which on compliance paperwork is worth more than it sounds. A version with a Bluetooth and IrDA printer is also available, for printing reports on site.

Where It Sits in the Range

It’s worth being direct, because specifying the wrong tier wastes money either way.

The testo 310 II covers boilers, hot water systems and gas heating plant. That’s most of the combustion equipment in a commercial or institutional building, and for that work, a more capable instrument adds cost without adding anything useful.

Where the application is industrial, such as gas turbines, engines, process plant or emissions compliance, the testo 340 and testo 350 add more gas sensors and higher measuring ranges. Talk to our Technical Consultants about the right instrument for industrial work.

Where It’s Used

Commercial and institutional plant rooms. Hospitals and aged care facilities. Hotels and accommodation. Schools and universities. Food processing plant with hot water systems. Commercial kitchens and laundries. Apartment and residential building plant. Swimming pool and leisure centre heating. Small industrial boilers. Gas water heaters and low temperature boilers. Marine and vessel hot water plant.