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£599.00 £718.80 (Inc. VAT)

Product Description

Testo 320B – Flue Gas Analyser (standard kit)


The testo 320 basic features all the essential functions for carrying out flue gas analysis on domestic heating systems, including flue draught, pressure measurements, and differential temperature measurement. The flue gas analyser is easy to use with its full colour graphic display featuring a user-friendly menu guidance. The analyser measures both O2 and CO (4,000ppm sensor fitted as standard) and can also display calculated parameters such as combustion ratio, CO2, etc.

Standard kit features include :

* 4,000ppm CO sensor with automatic pump shut off to help prevent saturation.
*10 user selectable fuels
*rechargable Li-ion battery
*tightness and let-by pressure test routines included in menu (requires pressure connection adaptor)
*Flow and return temperature measurement (using additional accessory probes)
*Soft carry case with shoulder strapx
*Independently tested according to EN 50379 Parts 1-3


  • High-resolution graphic display – The measurement menus and measurement values are presented in detail and always well legible.
  • Sensor monitoring – Integriated traffic light system which continuously monitors the sensor functionality.
  • Stamp of approval – The flue gas analyzer testo 320 is TÃœV-tested according to EN 50379, Parts 1-3
  • Automatic zeroing of sensor – Automatic zeroing of the gas sensor in only 30 seconds after starting, which can be cancelled if not required.
  • Lithium rechargeable battery – Operation with lithium rechargeable battery (1500 mAh) – no need to change battery, up to eight hours running time, charging via USB possible.
  • Attachment – Integrated magnets for fast attachment to burner.
  • Probe filter – Easy exchange of probe filter.
  • Memory – Up to 500 measurement protocols can be stored and called up in the memory of the testo 320.


The new testo 320 Rangeis a high-quality measuring instrument for efficient flue gas analysis. Its wide measuring range makes it a reliable partner for eliminating malfunctions and emergencies, monitoring legal limit values or for daily routine work servicing heating systems. The numerous measurement menus of the testo 320 are clearly structured. Standardised menu procedures, which are stored in the instrument specifically for your country, simplify operation – depending on which standards you are dealing with. This user-friendly feature is made truly convenient by the high resolution display. It allows a detailed presentation of the measurement procedures, is easily legible even under the worst conditions, and forms the basis for a graphical flue gas analysis – making your work on a heating system considerably easier.

The testo 320 has two measurement sensors for O2 and CO, as well as a temperature sensor integrated into the flue gas probe, for the direct measurement of temperature, O2 and CO. From these data, the instrument calculates all relevant flue gas measurement parameters such as CO2 value, degree of effectively and flue gas loss. Direct draught or pressure measurements are additionally possible. Using the fine pressure probe, the flue draught or gas pressure values can optionally be measured parallel to the flue gas measurement. Also available: Sensors for CO measurement with H2 compensation and COlow measurement. Using the respective probe, the CO2 content and the CO content in the surroundings can be measured.

Sensor zeroing in only 30 seconds

Thanks to the automatic zeroing or the gas sensor, the instrument is ready to measure shortly after being switched on – only 30 seconds to start. For the measurement parameters O2, CO, temperature and pressure, the testo 320 has been TÃœV-tested according to EN 50379, Parts 1-3.

The new flue gas analyser testo 320 solves every measurement task on a heating system. It offers numerous measurement menus, for example for flue gas, draught, differential pressure and ambient CO measurement. The large selection of variable probes makes the testo 320 even more efficient.

You have everything you need for complex measurements on heating systems in one instrument. With the testo 320, you comply with all legal guidelines, and measure on this basis


Technical Data
Storage temp. -20 to +50 °C
Oper. temp. -5 to +45 °C
Memory 500 readings
Display Colour graphic display with 240 x 320 Pixel
Weight 573 g
Dimensions L 240 x W 85 x H 65 mm
Warranty Instrument/probes/gas sensors:
24 months
Rech. batt.: 12 months


Technical Data
320 Measuring range
Accuracy ±1 Digit
Adjustment time t90
Temperature -40 to +1200 °C Accuracy: ±0,5°C (0 to 100°C)
Accuracy: ±0.5% of m.v. remaining range
0.1 °C -40 to +999,9°C
1 °C; from +1000°C:
Draught measurement -9.99 hPa to
+40.00 hPa
± 0.02 hPa or
± 5% of m.v. (at -0,50 to +0,60 hPa)
± 0.03 hPa (0.61 to 3.00 hPa)
± 1.5% of m.v. (at 3.01 to 40.00 hPa))
0.01 hPa
with fine draught option
0.001 hPa
Pressure measurement 0 to +300 hPa ±0.5 hPa (0.0 to +500 hPa)
± 1 % of m.v. (at 50.1 to 100.0 hPa)
± 1,5 % of m.v. (at 100,1 to 300,0 hPa)
0.1 hPa with fine pressure
option 0.01
O2measurement 0 to 21 vol.% ± 0.2 vol.% 01 vol. % < 20 sec
CO measurement
(without H2 compensation)
0 to 4000 ppm ±3 ppm (0 to 30 ppm)
±10 % of M.V. (31 to 200 ppm)
±20 ppm (201 – 400 ppm)
±5 % of M.V. (401 to 2000 ppm)
±10 % of M.V. (2001 to 4000 ppm)
1 ppm < 60 sec
CO measurement
(with H2 compensation)
0 to 8000 ppm ±3 ppm (0 to 30 ppm)
±10 % of M.V. (31 to 200 ppm)
±20 ppm (201 – 400 ppm)
±5 % of M.V. (401 to 2000 ppm)
±10 % of M.V. (2001 to 8000 ppm
)1 ppm < 40 sec
Efficiency testing (Eta) 0 to 120 % 01 %
Exhaust gas loss 0 to 99.9 % 01 %
CO2 determination
digital calculation from O2
0 to CO2 max ± 0.2 vol.% 01 %
Option COlow
0 to 500 ppm ±2 ppm (0 to 39 ppm)
±5% of m.v. (40 to 500 ppm)
01 ppm < 40 sec
Ambient CO measurement
(with CO probe)
0 to 500 ppm ±5 ppm (0 to 100 ppm)
±5 % of m.v. (>100 ppm)
1 ppm
Gas leak measurement
for combustible
gases (with gas
leak detector probe)
0 to 10,000 ppm
CH4 / C3H8
Optical display (LED)
Audible alarm via buzzer
< 2 sec
Ambient CO2
(with ambient CO2
0 to to 1 vol. %
0 to 10,000 ppm
± 50 ppm or ±2% of m.v.
(0 to 5000 ppm)
± 100 ppm or ±3% of m.v.
(5001 to 100000
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