Gases PRO Sensor Board (Calibrated)
This platform enables the user to implement pollution, air quality, industrial, environmental or farming projects with high requirements in terms of high accuracy, reliability and measurement range as the sensors come calibrated from factory. The Gases PRO line is available for both Waspmote and Plug & Sense!.
So we offer to our clients two different sensor boards in order to measure gas levels: Gases Sensor Board (Gases) and Gases PRO Sensor Board (Gases PRO).
Comparative between Gases and Gases PRO sensor boards:
- Gases PRO integrates 17 different gas sensors. Gases integrates 12. See the complete list of parameters in the tables below.
- Gases PRO is useful to measure the exact value in ppm's of a gas concentration. The Gases line provides just the level of concentration low / medium / high. Complete accuracy ranges are shown in the table below.
- Gases PRO is meant to be used in applications that require accurate readings and exact concentrations thus its sensors are more expensive than the Gases regular version that just provides average levels.
- A Particle Matter Sensor -commonly known as "Dust Sensor"- has been integrated in the Gases PRO board. This sensor allows to measure PM1, PM2.5, and PM10 particles. This sensor comes also calibrated from factory.
- Gases PRO is available for the Plug & Sense! product line (as Smart Environment PRO), while Gases is only offered for Waspmote OEM.
Should I choose Gases or Gases PRO?
Libelium created 2 different systems in terms of accuracy and pricing. The customer should consider Gases PRO if he needs maximum performance sensors for metering in accurate ppm or percentage. If the project just needs to detect gas presence or gas levels, the standard Gases Sensor Board can be enough.
The Gases PRO Sensor Board can read up to 17 gas sensors; it also has a high-end sensor for 3 parameters, temperature, humidity and pressure.
Gases PRO v3.0
Accuracy values have been calculated at average conditions: 20ºC / 101300 Pa. Accuracy levels may differ with different temperature and pressure levels, aging and in presence of third type of gases which cause cross sensitivity. See the "Calibration" chapter for more detail.
How are the Gases PRO sensors calibrated?
All the Gases PRO sensors are linear, so they behave according to a simple line like y = f(x) = m·x + c. On the other hand, the Gases Sensor Board sensors show a logarithmic response, which is harder to handle.
All the gas sensors for Gases PRO are calibrated by the sensor manufacturers, in their laboratories. A two-point calibration process is performed to get maximum accuracy, with controlled concentrations of gas in vacuum chambers. Due to the linear nature of the sensors, those 2 points are enough to correct the 2 possible drifts in m (slope) and c (constant offset). Our sensor manufacturers provide a calibration certificate for each individual sensor, with two calibration parameters. Libelium stores these parameters in an EEPROM, non-volatile memory chip inside each gas sensor. When the user performs a sensor reading, the software system designed by Libelium reads the sensor signal and the 2 parameters. All these 3 values are processed by the system. After this, a temperature compensation calculation is applied too. From this data we obtain the concentration value in ppm's (which is the final value we want to measure).
The Temperature, Humidity and Pressure sensor for Gases PRO is calibrated in factory too. There are 3 calibration points for temperature, 6 points for humidity and 9 points for pressure. These 3 parameters are automatically inter-compensated and this way the user gets extreme accuracy.