Catalyst of platinum filament (platinum, etc.) contacts with air containing flammable gas to cause combustion.

Sensor is comprised of detecting sensor that is thermal coasted with special catalyst that surrounds the platinum coil with high purity and temperature compensating circuit.

When flammable gas contacts the surface of sensor, gas is combusted in the concentration that is lower than LEL.
Heat occurs in the course of combustion increasing the temperature of platinum coil and also the resistance value in proportion of concentration.
Concentration of gas is detecting the changes in current in the unbalanced voltage of wheatstone bridge for the changes in gas detecting sensor and temperature compensating sensor.

• Output is proportion with the gas concentration representing linear output from the LED concentration.
• Outstanding responding characteristics as well as long-term stability
• No influence from changes in temperature and humidity nearby

Molecules such as flammable gas are attached on the surface of the metal oxidized semi-conductor changing the electronic structure in the semi-conductor and increasing the electronic conductivity.

Sintered metal oxidized semi-conductor is comprised of semi-conductor substances (metal oxidized substances) surrounding a pair of platinum coil.

When gas contacts the metal oxidized semi-conductor, there is a movement of free electrons in the semiconductor increasing the electronic conductivity of cell and detecting such an increase with the output from platinum coil electrolysis in the metal oxidized substances.

• Sensitively react with low concentration and long life span of the sensor
• Poor compensating ability in the conditions nearby

Used for the toxic gas detector.
Gas expanded and absorbed in the electrolysis through the constant potential of gas penetration is oxidized using the current occurring at this moment to measure the gas concentration.
Constant potential electrolysis method is a sensor to measure the gas concentration by detecting current produced when gas is electrolyzed on the specific constant potential.

Comprised of three gas electrolysis (reacting electrolysis, referential electrolysis, and opposite pole electrolysis) and electrolysis in the plastic container with chemical resistance.

Constant potential electrolysis sensor is in a structure covered with diaphragm such as electrolysis, and the gas to be detected penetrates the diaphragm and absorbed in the reacting electrolysis from electro-chemical catalyst.
Hereupon, current produced by the constant potential flows with resistance connected between reacting electrolysis and opposite pole electrolysis, and electrolysis generated hereof is proportional to each of the gas concentrations.

• Sensitively react in low concentration
• Linear output feature
• Outstanding stableness and safety
• Convenient to deal with as a small sized and light-weighted substance

With luxury jewelry (silver or gold) as anode and the non-metal substances (lead or zinc) as cathode, this substance is deposited in the electrolysis solution (caustic soda) as it is used for the detection of oxygen.

Diaphragm galvanic electrolysis is comprised of comparative poles and electrolysis solution.

Diaphragm on the electrode is a gas penetrative layer that gas to be measured if it is mixed with in the air near the electrode is dissolved in electrolytic solution by penetrating this layer. At this time, galvanic battery is created in the electrode causing the potential difference. With the galvanic battery created in the electrode, there are reactions such as oxidization, reduction, and electrolysis while having the electronic sign created by them with output in electrode.

• Used for detection of oxygen
• High preciseness of measurement

Electrodes are in a structure containing and sealing the reacting electrode and opposite pole electrode with inner solution and diaphragm. This diaphragm has a feature to penetrate the measured gas.
When electrode contacts with measured gas, gas penetrates diaphragm and comes to inside to react with inner solution while causing changes in potential, and these changes in electronic sign are detected.
Inner solution and reacting electrode differ depending on the gas to be detected.

• Maintain sensitivity for a long time
• Fast reacting speed
• Outstanding stability

Light absorption of the gas molecules is measured converting the concentration. Using the ultraviolet ray absorption characteristics of waves with other polyatomic molecular gas, this method is to measure the absorption rate of ultraviolet rays in the relevant for the concentration converting it to the concentration. This method is not influenced by those other than measured gases.

• Very high preciseness in measurement
• Very long life span
• Relatively high price of sensor