Section 2: Sensor and Sampling Techniques
inside these materials.
•Try to run pipes to the sensor upwards, so that contaminants tend to fall back into the main line.
•Keep the length of the sample line to the sensor as short as possible.
•Use small diameter pipes (1/4” or 1/8” OD).
•Use sufficient flow rates (e.g. 1 l/min with 6 feet of 1/8” piping is adequate). The flow rate will influence the systems’ response time.
•Do not install any devices upstream of the sensor, such as other measuring systems, flow meters etc., which are not absolutely necessary as these are potential leak sources.
•Installation of a coalescing and / or particulate filter ahead of the sensor is desirable to prevent any liquid or particulate contamination of the sensor.
•If filters are used upstream of the sensor, make sure these contain
•If pressure regulators, shut off valves etc. are used upstream of the sensor, make sure these do not contain rubber or other hygroscopic materials.
2.4 Mechanical Installation
The sensor probe has two thread sizes for mounting to the sample cavity where the dewpoint will be measured, see appendix C. Various optional fittings are available for direct connection into existing system openings, refer to appendix D. Ask your representative for a Sample Cell, if you do not have the ability to provide an appropriate sample cavity mounting. If the ¾”x16 thread is used then the sensor will seal against the wall of the sample cell with the provided Viton A
The sensor can be removed from the fitting by unscrewing it. Make sure that the sensor is securely fastened to the fitting (the tension washer should be compressed), so that it does not come loose during use.
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