Dewchecker 2.0. Operating instructions. messen steuern automatisieren - messen steuern automatisieren - messen steuern - automatisieren

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1 Operating instructions Dewchecker 2.0 messen steuern automatisieren - messen steuern automatisieren - messen steuern - automatisieren

2 1. Application The Dewchecker is suitable for dewpoint measuring of gasses at atmospheric pressure. The Dewchecker is equiped with 2 seperate dewpoint measuring systems. ➊ ➋ Cooled mirror system Capacitance measuring system with output ma 80 DP DP 2. Operation 2.1 The measuring prepares Attaching equipment at 230 Vac/50 Hz Attaching measuring gas at the V4A tube (6 mm ø) or thick-wall teflon tube Important: The gas dewpoint temperature must be below the ambient temperature. The probe connecting piece should assembled up to avoid condensed water. Condensed water in the gas pipe to the Dewchecker gives faulty measurements. The gas supply must be tight! Respect: At the measuring of poisonous, combustible gasses bad for health the gas must be had a laxative effect, so that no danger can arise for the operator or the surroundings at the exit of the device. Setting to work: Power switches on, assembled on the back side. Having measuring gas approx. 2-3 minutes until the gasflow is representative in the measuring chamber. The gasflow is correct if the flowmeter indicates approx. 60 l/h. The gas dewpoint temperature is below, before begin of the measuring must be draw in longer the measuring gas.

3 2.2 Measuring Note: The switch "Hold" in position "On" storaged the ascertained dewpoint temperature on the indicator mirror. The measuring is active by pressing the button "Test". The mirror is cooled as long until the dewpoint temperature of the measuring gas is reached. A ring moisture is result on the mirror at this moment. On the indicator "Mirror" the dewpoint temperature is storaged and readable. Button Test Button Test = rapit cooling 30 C/min = slow cooling 10 C/min 3. Adjusting the 2. Measuring system in comparision with the 1. Cooling mirror system It is possible to adjust the 2. measurement range in comparison with the mirror system between ( DP). Proceed as follows: Attach the measuring gas at the Dewchecker. The switch to position On. Press the button for "Test" in position as long until the dewpoint ring is seen in the mirror and adjust with button in position. The dewpoint temperature of the measuring gas can be stored and read from the digital voltmeter "mirror" into middle position of the test button. With the Potentiometer "Zero" make the adjustment for the 2. Measuring system. The sensor can't be coordinated in the measurement range DP. We recommend to send the Dewchecker to MESA before calibration twice a year. This recommendation can vary depending on operating conditions. 4. Maintenance The maintenance of the device is very simple and confines itself to only some points: Cleaning of the mirror

4 No wetting liquids (e.g. washing-up liquid) may be used for cleaning the mirror. If possible, rub off the mirror with a cotton bud only dryly. In case of stronger pollution use some alcohol. If the contrast effect on the mirror has decreased because of dirt or the use of a wetting liquid: First clean it with alcohol, afterwards with Polish paste, then polish it with cotton buds (Polish paste you ll find at accessories). Replacing the filters If the gas flow decrease < 60 l/h, and a proper measuring is no longer possible, check the filter pads. The Dewchecker is equiped with 2 filters: Input filter unit at the back. This filter needs a cotton inserted (MESA item No.: ) A fine filter at the case front. This filter needs a filterpiece (MESA item No.: ). If the measuring gas is very dusty or containing soot, use an additional line filter in the pipe line. This filter needs some cotton. 5. Faults, their causes and its elimination: Mismeasurement by condensate formation in the measuring gas feed pipe: If the dewpoint of the measuring gas is higher than the ambient temperature, or higher than a part of the measuring system, is produce condensate formation. At the following cases condensate formation takes place: The gas pipe line has contact with cold components (e.g. water pipe) The gas pipe line runs near an open window, through cold rooms or zones etc. The Dewchecker was taken from a cold room and the temperature of gas touching parts are below the dewpoint of the measuring gas. Remedy: If you find condensate, use the system for a time for measuring normal room air, until the Dewchecker is dry again. Use before the beginning of the gas measuring for a time room air. This dewpoint value give you the assurance that the system is dry again.

5 Faulty measurings by leaks Of course the measuring system must be tight! If you have the suspicion, that ambient air is mixed, a tightness examination is necessary. Use a short piece of tube at the gas output of the Dewchecker and keep the open end into a vessel filled with water. Close the gas input that no gas comes into the system. If the system is tight, no bubbles will appear under water. Mirror disk broken or damaged In this case: As long as you still see the contrast picture (dewpoint ring) properly and the mirror doesn't come loose of its underground, the Dewchecker works without restriction of the precision. Too low suction capacity of the measuring gas pump If the filters are closed, the pump doesn t have suction power enough. You can bend this damage forward by changing the filters on time. If the pump is defect, send the device to us for repair.