Measuring and Monitoring Dewpoint in Point-Of-Use Applications
In most facilities you will find that, when discussing compressed air systems, the entire network is divided into sides: supply and demand.
When speaking of the supply side we talk about the compressors and air treatment equipment up to the flow or pressure controller. Here dewpoint transmitters that provide analog signals can be built into the dryer control system or installed in-line, either before or after the receiver tank.
The demand side includes everything that is found after the receiver tank or the distribution and storage systems. In the distribution network and before critical end-use applications we commonly find fixed mount instruments that provide a local display, datalogging capabilities & alarm relays.
Portable devices are becoming more popular because they’re great tools for performing quality audits, verifying dryer performance and checking the instrument calibration.
Dewpoint and Point-Of-Use Applications
For point-of-use dewpoint measurements, there are two predominant options available: direct in-line insertion or sample extraction. As with most things, both methods boast advantages and disadvantages.
Direct In-line insertion
Direct insertion is when the probe is installed through a threaded connection or “T” in the line.
With line pressure fluctuations and sensor removal being the disadvantages of this method, the advantages of direct insertion are:
- Ease of installation
- No accessories required
- No venting or loss of the compressed air
Sample Extraction Sample extraction isolates the sensor from the mainline through stainless steel sample lines and sample cells. This is a popular method because when the sensor is separated from the mainline the pressure is regulated, which effects the dewpoint reading.
Another advantage of sample extraction is the ease with which sensors are installed and removed.
Questions to Ask When Selecting a Dewpoint Instrument
Before you make your decision on which instrument you will be installing to measure and monitor dewpoint, you should take the following questions into consideration.
- What is the expected dewpoint level at the intended measurement location?
- What are the pressure and temperature ranges?
- Should the instrument be portable or mounted?
- Does the instrument offer any other functionality?
This should give you a much clearer idea of which option is right for you & will meet your needs. You can also discuss your needs with our team. Book a site visit or request a quote to help you get on par: firstname.lastname@example.org.