News — Sensor

Senseair CO2 Sensor Pressure Dependence

All infrared (NDIR) CO2 sensors have a dependence on pressure. This is because of the physics principle used to measure CO2 concentration. The NDIR type of sensor measures the IR radiation absorbed by CO2 molecules, which corresponds to the mole concentration. When pressure increases, the number of molecules in a given volume also increases linearly. Conversely, when pressure decreases (higher altitudes, for example) the number of molecules decrease. This app note includes both general information about Senseair sensors and pressure, as well as the equation for computing true CO2 level readings at various pressures useful for any NDIR CO2 sensor....

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Sensors and Anti-Static Bags

Sensors and Anti-Static Bags

While working with a customer who was having a problem with a sensor, we learned that the customer had set the sensor on top of the anti-static bag it was delivered in. He confirmed this by successfully testing a second sensor without the bag underneath it. Sensors should never be powered on or even laid on top of an anti-static bag. To create the anti-static effect, the black bags or silver bags are slightly conductive, forming what is known as a Faraday Cage around the item to be protected avoiding any discharges from being deposited onto the protected devices as...

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Measuring CO2 in Exhaled Breath to Help Save Lives

Measuring CO2 in Exhaled Breath to Help Save Lives

Capnography is the measuring and monitoring of the carbon dioxide levels in exhaled breath. In healthy individuals, the difference between the CO2 exhaled and CO2 levels in arterial blood are proportional. Therefore, by monitoring the waveform of CO2 levels on a capnogram (an electronic capnography monitor) over time, medical personnel like anesthesiologists or paramedics can use the information to monitor a patient. Sudden changes in end-tidal CO2 (ETCO2, the level of carbon dioxide released at the end of expiration) may signify changes in a patient’s heart or lung functions. Non-dispersive infra-red (NDIR) CO2 sensors are at the heart of virtually...

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CO2 Sensor ABC Calibration Explained

The ABC - Automatic Background Calibration algorithm allows the CO2 sensor to dynamically shift its CO2 reading by a constant.

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