Various sensor products
NAP－21A
NAP-21A is a thermal-conductive type gas sensor to detect gases making use of the variation of the thermal conductivity of a target gas. This sensor is suitable for detection of highly concentrated gases more than percent order or inert gases that are not chemically reacted.
Ratings and Gas sensitivity
| Items |
NAP-21A |
| Supply voltage |
DC 1.8 ± 0.1V |
| Current |
120 ~ 130mA (1.8V applied) |
| Ambient Temp. & humidity in operation |
-10 ~ +50oC, 95％RH or less |
| Ambient Temp. & humidity in operation |
-20 ~ +60oC, 99％RH or less |
| CO2 gas sensitivity |
0.2mV / ％CO2 |
This sensor detects the changes of outputs when the thermal conductivity of the ambient atmosphere becomes different from the conductivity of the air. More specifically, the output shifts towards (+) side when the target gas has a larger molecular weight than the air, and shifts towards (-) side in case of a smaller molecular weight. The output characteristic of this sensor shows excellent linearity to the gas concentrations that is good enough to measure concentrations up to 100%. However, this sensor is humidity-dependent (As “humidity is “steam” which makes the output shift towards (-) side.), a compensation circuit would be needed upon designing circuits. Because of these characteristics, this sensor is suitable for CO2 gas measurement & CO2 gas monitoring in containers for vegetables & fruits etc.
