News — Sensor

Recently we had a customer contact us regarding opening a serial connection via Python to our CM-0039 CO2 Probe. The Probe is a ruggedized enclosure for our SenseAir CO2 sensors that allow USB tethered, real-time reading of CO2 levels from a PC. While we don’t have any pre-written Python code to talk to the Probe, with a bit of work, the customer should be able to do it on his own. The same is true for any programming language that will let you communicate with a serial device. The first thing to do is to verify that the hardware is...

If you cannot communicate between your sensor module or CO2 meter and the GasLab® Software on your computer, the problem may be caused by Windows not recognizing the correct drivers needed to create a chain from USB -> FTDI -> UART in order to communicate with the device. The drivers create a virtual COM port. If the device is plugged in before GasLab is installed, the correct drivers will not be found, even if GasLab is installed later. The solution is to uninstall the old (usually incorrect) drivers manually, install GasLab if it is not already installed, then plug your...

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....

Many clients use our Arduino UART examples and Arduino source code to connect the popular SenseAir K-30 sensor to Arduino boards. However, these examples were all created before the SenseAir S8 CO2 Sensor was developed. So we were surprised when a client recently wrote us:   "To my surprise, the script you give for the K30 sensor works out of the box with the S8! Why don't you mention it in the app note? Had I known that from the start, I wouldn't have bothered you about which sensor to buy..." Frankly, we were a bit sheepish. In all the...

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...