testo 380

A System, Not an Instrument

It’s worth understanding this before comparing it to anything else, because it changes what you’re buying.

The testo 380 has two components. The testo 380 fine particle analyser, with its fine particle probe, does the particulate measurement. A testo 330-2 LL flue gas analyser sits alongside it as the control centre, and handles the oxygen and carbon monoxide measurement. The testo 380 must be used with the testo 330-2 LL, and the 330-2 LL can also be taken out of the case and used on its own for flue gas analysis on oil and gas systems.

Together, they measure particulate, oxygen and carbon monoxide in parallel, and display all of it in real time. That parallel measurement is the point. Particulate alone tells you the emission. Particulate alongside oxygen and carbon monoxide tells you why, because incomplete combustion is what produces the particulate in the first place.

Particulate Measurement Is Normally a Laboratory Job

This is the argument for the system, and it’s about workflow rather than technology.

Traditional particulate measurement means collecting a sample on site, sending it away and waiting for the result. By the time it arrives, the technician has left, and any adjustment has already been made on judgement rather than data.

The testo 380 gives the result on site, in real time. The effect of any change to the boiler shows on the display straight away, so a solid fuel system can be adjusted, measured again and confirmed within one visit. On commissioning or optimisation work, that’s the difference between tuning a system and guessing at it.

An official measurement takes about 30 minutes, and a tightness test of the measurement system is needed beforehand.

The Probe Does the Difficult Part

Particulate measurement in flue gas is hard for two reasons, and both are handled in the probe.

The first is condensation. Flue gas is hot and wet. If it cools in the sampling path, moisture condenses and takes particulate with it, so the sample reaching the instrument isn’t the one that entered the probe. The probe shaft is heated to a constant 120°C to prevent that.

The second is concentration. Raw flue gas particulate can be well outside what a measuring instrument can handle directly. A patented rotation diluter, made of technical ceramics and heated to 80°C, is built into the probe. It mixes the raw gas with a defined amount of fresh air, which keeps contamination of the gas paths and the whole system to a minimum.

The fine particle sensor then measures the mass of the particles directly. The particles land on an oscillating sensor, and the change in its frequency gives the particle mass, fast enough to show readings in real time.

One probe handles sampling, temperature, draught, heating and dilution, so no other probes are needed for fine particle measurement.

Cleaning and Maintenance

This is a small point, but it matters on an instrument handling soot.

Because the rotation diluter keeps contamination to a minimum, cleaning is done with conventional household cotton buds. No specialist cleaning kit is needed. Testo describes the system as particularly economical to operate and maintain.

Certification and Its Origin

The system is TÜV tested for limit value levels 1 and 2, and to VDI 4206 Sheet 2. It’s approved for fuels in instrument classes A, B and C of VDI 4206-2, which covers fuel groups 1 to 8: coal, lignite, peat, natural wood in all forms, wood briquettes and pellets, treated and glued wood, and straw and other plant materials.

Those references come from the German regulatory framework, specifically the first German Federal Emission Control Ordinance (1st BImSchV), which sets particulate limits for solid fuel systems. The instrument has pre saved measurement menus and step by step guidance for those procedures.

Australia has no direct equivalent, so here the certification shows measurement capability and traceability, rather than meeting a local legal requirement. That’s worth knowing when specifying: the measurement is sound, but the compliance framework is German.

Where It’s Used

Solid fuel fired boilers and heating systems. Biomass and wood pellet plant. Wood chip fired systems. Oil fired heating plant. Gas fired systems where particulate is a concern. Commissioning and optimisation of solid fuel combustion. Service and inspection work on solid fuel appliances. Emissions checks where a laboratory turnaround isn’t practical.