testo 308 - Smoke tester

Order-Nr.  0632 0308

Price on Request
  • Fully automatic soot count measurements

  • User-friendly menu guide; easy-to-read, backlit display; easy-to-change soot filter rolls

  • TÜV certified

  • Optional print out on site

The testo 308 is designed to provide you with quick and easy soot particle measurements. Gone are the days of manual or semi-manual measurements. Benefit from groundbreaking technology. The testo 308 smoke tester provides you with digital readings for easy documentation.


Product Description

There’s a rule that generally applies for all oil heating systems: the less soot there is, the better the combustion. That’s why soot count measurements are an integral part of the work carried out by heating engineers.

What your testo 308 smoke tester has to offer

Manual or semi-manual measurement systems are an extremely time-consuming and laborious method of determining the number of soot particles. Not only that, such measurements are often inaccurate and difficult to document too. The state-of-the-art testo 308 digital smoke meter can help you to solve not one, not two, but a whole bunch of problems in one fell swoop.

The testo 308 smoke meter measures the number of soot particles using the old manual method, the filter test. The difference that makes all the difference, however, is that this is performed fully automatically. The results are then presented as a digital reading on the tester’s backlit display providing you not only with extremely reliable readings, but saving you precious time too.

The optional testo turbo printer can be used to print out on site via the smoke tester’s infrared interface for quick and easy documentation.

Delivery Scope

testo 308 smoke tester, rechargeable battery, calibration certificate.

Technical Data

General technical data


600 g incl. battery


270 x 63 x 120 mm

Operating temperature

0 to +40 °C

Protection class


Pump capacity

1.63 ± 0.1 l

Reference filter

at 990 mbar and +20 °C ambient temperature

Gas sampling

Stainless steel pipe ca. 220 mm, rubber hose 100 mm


EU-guideline 2004/108/EG

Display function

Segment display

Display ligthing

with background illumination

Storage battery type

Lithium ion battery, 2600 mA

Battery life

45 individual measurements

Battery charge

in the instrument via mains unit or externally by charger

Storage temperature

-20 to +50 °C

Smoke number - Photodiode

Measuring range

0 to 6 RZ


±0,2 RZ


±0,1 RZ


Product sets

Price on Request



Spare battery 2600 mA

Order Number: 0515 0107

ZAR 1,040.60
incl. VAT  ZAR 1,196.69
Spare soot filter paper; 8 paper rolls

Order Number: 0554 0146

ZAR 614.90
incl. VAT  ZAR 707.14
testo fast printer IRDA

Order Number: 0554 0549

ZAR 5,865.20
incl. VAT  ZAR 6,744.98
ZAR 1,158.85
incl. VAT  ZAR 1,332.68
Cone with fixing screw

Order Number: 0554 9010

International mains unit

Order Number: 0554 1096

ZAR 1,182.50
incl. VAT  ZAR 1,359.88


Measuring the flue gas parameters of the burner (CO, O2, and temperature, etc.)

The soot count is an important performance characteristic and in many countries an established measuring requirement. In the case of oil heating systems, this is carried out before the actual flue gas loss and CO/CO2 measurement. The soot count is a primary indicator of the quality of combustion in an oil heating system: the less soot there is, the better the combustion. Soot is a black solid comprising up to 99.5% carbon. The level of soot contamination in flue gas is established by the degree of blackening of a measurement spot on white filter paper.

The defined flue gas quantity of 1.63 l is removed through a probe shaft by means of a manually operated hand pump, or semi-automatic and electronic measuring instrument and hits the filter paper. The blackening on the filter paper is then compared with the 10 grey shades of a soot count scale.

This measurement is taken three times in a row to establish an average value and allow comparison with the maximum permitted soot count; this is significant for determining the operational reliability and therefore approval of an oil heating system.

The soot spot can also be tested for oil deposits by dripping acetone on the edge of the spot. If a yellow discolouration is discerned on the soot measurement spot, this indicates oil deposits.

Price on Request