Constant Flow Sampling
For process and environmental sampling aimed at analyzing the concentration of specific gases, a fixed flow rate is often used. The sampled volume is ultimately determined by a simple dry gas meter. In principle, these are often relatively straightforward methods. However, several important factors should be considered:
- If a truly constant sampling flow is desired, it is important that the sampling system compensates for pressure drop variations. Flow rate is often critical when sampling over filter heads and, to a lesser extent, over absorption columns or absorption liquid in impingers.
- In process and environmental measurements, final concentrations are usually expressed under standard conditions. Therefore, knowing the pressure and temperature at the dry gas meter is also essential.
QB1 Sampling Pump
For such applications, Ravebo offers the QB1 sampling pump. These are easily adjustable pressure-compensated constant flow pumps. The gas meter has a temperature sensor and operates at atmospheric pressure, allowing you to easily determine the sampled volume in normalized liters. Flow is adjusted using rotameters.
For added convenience and the benefits of automatic flow and volume measurement, there is the QB1e. This version includes electronics that allow the sampling process to be programmed. During sampling, the flow is digitally measured based on pulses from the gas meter, making it easier to manually set a precise flow.
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Parameters
The QB1e displays the following parameters:
- Flow in nl/min and actual flow in l/min;
- Volume in nl and actual volume in l;
- Ambient pressure;
- Medium temperature in the gas meter.
At the end of the sampling, all these data points are saved to memory (including date and time) and can be retrieved on the display. It is also possible to read the data via a Bluetooth application.
Want to Know More?
Would you like to learn more about sampling pumps, calibration, or measurements? We are happy to assist. If you have any other questions, our team is ready to help! Call us or fill in the contact form below, and we will get in touch with you.