By employing 6 different types of sensor, noxious, explosive and non-combustible gases and vapours can be measured.

Display of the measured gas concentration and the adjustable alarm thresholds, are shown on a multi-colour graphic display. The keyboard input is by way of a touchpad.

A current signal is generated that is proportional to the measured concentration of gas, which is transmitted to an evaluation unit placed in a safe area, away from any dangers of explosion.

TOX sensor

The TOX sensor is a measurement system with electro-chemical cell, where the sampled gas is measured by diffusion. In the case of oxygen measurement the oxygen content is in an electrolyte, thus producing a small flow of current (electro-chemical process).

At a constant air pressure, this current is directly proportional to the oxygen concentration in the sampled air.

TGS sensor

The TGS sensor contains a semiconductor sensor, which is ?constructed on SnO2-sintered N-substrate.

When combustible or reducing gases are absorbed by the surface of the sensor, the concentration of the test gas is determined by the change in conductivity.

The IR sensor

The test gas flows through a measurement chamber that incorporates an IR radiating source and a two-channel

infrared detector. The intensitiy of the infrared radiation is reduced as it passes through the gas molecules.The concentration of the gas can then be calculated by the magnitude of the reduction in intensity.

Since only absorption of the wavelength specific to the gas under test in relation to the wavelength not absorbed by a test gas is considered, interference due to dust, ageing etc., is almost compensated.

GOW sensor

The GOW sensor functions on the principle of thermal conductivity. Two rhenium-tungsten resistors are used as a measuring element, where the comparison element is subjected to normal ambient air and the measuring element is subjected to the test gas. Any change in the concentration of gas at the measurement element, causes a change in temperature, which is due to the variation of conductivity.

The resultant change in resistance is a direct measure of the gas concentration.

The PID sensor

The sampled gas flows through a measurement chamber, that incorporates a UV radiating source and a pair of

electrodes with opposing polarity. The gas molecules to be detected are ionized by the UV radiation.

The resulting positively charged molecules and the electrons are attracted to the relevant electrode. The current generated is a measure of the gas concentration.

Using the PID measuring head, volatile organic compounds (VOC) can be measured, the ionisation potential of which is less than the energy in the UV radiating source (10,6?eV), e.g. aromatic hydrocarbons like toluol (C7H8) and xylene (C8H10) as well as chlorinated hydrocarbons like trichloroethylene (CHCl3). The detection of toxic gases like phosphine (PH3) is also possible.

VQ sensor

The head of the VQ sensor functions on the principle of heat ?reaction. When combustible or reducing gases or ?vapours come in contact with the measuring element, they are subjected to catalytic ?combustion, which ?causes a rise in temperature; this rise causes a change in the resistance of the measuring element which is used as a measure of the component of gas being tested.

The inert element is for compensating the temperature and conduc?tivity of the test gas.