home page tog menu

Tog Tester

An instrument to measure the thermal resistance of textiles in the range from 1 to 5 tog. using the comparator principle (Principles of tog testing).

The instrument is a simplified version of the original "Shirley Togmeter", omitting the forced air flow and the fixed-opening cold-plate. It consists of a laminated hotplate and reference board assembly with a black anodised aluminium surface, a custom micro-controller PCB and a lightweight 'cold plate' air temperature sensor. The instrument gives a direct reading of measured tog value. For methods which require correction for 'air tog' this must be calculated by the user. It has a USB port which can be used with a computer to make a continuous record of temperatures etc. during the test. Temperature control is automatic, but unlike the other instruments there is no built in test procedure, once thermal equilibrium has been achieved it gives a continuous display of measured tog value.

Tog Comparator


Place a conditioned test piece on the hotplate. Place the cold plate in the appropriate position for the test being carried out.

The display will initially indicate the instrument temperatures as it approaches equilibrium, then it will indicate the measured tog value. Record the value every 15 minutes until a stable value has been reached over three successive readings.

If you are doing an open test, then you will have previously determined the air tog value for the method, which must be subtracted from the indicated value.

Air conditioning

The instrument should be used in an air conditioned room. Short term small fluctuations in temperature can influence the tog reading: care must be taken to ensure the air temperature is adequately stable. Air conditioning requirements


Instrument complete with delivery and installation in the mainland UK is 2000
Does not include air conditioning, reference materials etc. Price excludes VAT, which for EU customers is charged at the UK rate. For overseas orders, please call.

Technical details

This is a precision instrument requiring minimal calibration and is capable of 1% accuracy given suitable environmental controls.
Hotplate temperature 33C 0.1C
Temperature variations across surface and between plates less than 0.02C
Over-temperature protection on heater
Heat output during test 1-20W.
Absolute temperature sensing by platinum resistance sensor with chopper stabilised amplifier giving stability of around 0.1 per year.
The instrument measures the temperatures at the centre of the hotplate only. USB port: provides simulated COM port to PC and outputs tog and temperature data every 20 sec.


Warm-up time approx 3 hours.
Test time: approx 2.5 hours

All system temperatures over entire measurement cycle recorded for validation.
Tog value displayed on built-in LCD. Compliant with CE regulations for electrical safety and EMC.