FAQs

Please refer to the following FAQs before contacting us.
If your question is not listed below, click "Contact Us" to submit your question.

What kinds of gas sensors exist?

There are several types such as semiconductor, hot-wire, electro-chemical, solid electrolyte, and infrared.

What are the merits of the semiconductor gas sensors?

High sensitivity to low concentration gas, low cost, and long life.

What are the demerits of the semiconductor gas sensors?

Influenced by ambient temperature and humidity, and low selectivity.

What is the detection principle of semiconductor gas sensors?

Click here.

What are your gas sensors used for?

For gas leak detectors, air conditioners, air purifiers, alcohol checkers, various measurement equipment, etc.

In what range of concentration can FIS sensors measure the gas?

Though it depends on the kind of gas, our gas sensors can measure gas in the range of tens ppb to tens of thousands of ppm.

What is the life of the semiconductor gas sensor?

The life is semi-permanent if used under usual ambient atmospheric conditions. The sensitivity may change from a long-term view point.

What is "gas sensitivity"?

It is (Rs in clean air)/(Rs in gas), where Rs means Sensor Resistance. Since Rs generally decreases in gas, the gas sensitivity is below 1.

What is "gas response"?

It is the time for the sensor to respond after the gas reaches the sensor.

What is "initial action"?

It is the sensor behavior from power-on to the ready status.

What is "noise gases"?

All the gases except the target detection gas. Such noise gases may exist in usual ambient air.

Can your gas sensor detect inactive gas such as helium?

Unfortunately, semiconductor gas sensor cannot detect inactive gases.

The humidity has an effect on the sensor. Why?

Ambient humidity (water vapor) can be considered as a kind of gas.

Can your gas sensors be used without oxygen?

Oxygen is required. Use the sensor under usual ambient atmosphere.

What is the sensing material?

Basically, tin oxides. Other materials are tungsten oxides, indium oxides, etc.

Can pins of the sensor be bend or cut?

Do not bend or cut the pins because the sensor will be mechanically shocked.

Can the sensor be soldered on the printed circuit board with a soldering bath?

Manual soldering is recommendable to avoid the solder's flux from influencing the sensor.

Does your sensor have intrinsically safe construction?

No, you need such construction housing separately.

The sensor is warm or hot. Should we cool it down?

The sensor should be heated to detect gases. Cooling down with fans, etc. will change the sensitivity.

If the specified heater voltage is changed, what will happen?

The sensing element temperature will be changed, then the cross sensitivity will also be changed.

What happens if the sensor is exposed to very high concentration gas?

The heater may deteriorate so that the operating temperature cannot be controlled.

Do you have the cross-sensitivity data?

Refer to PDF sensor data by clicking here "Gas Sensors".

Have you obtained ISO14000 and ISO9001?

Yes, we have. Click here "Environment and Quality" for details.