Thunder Scientific 5A-1MP, Руководство по эксплуатации и техническому обслуживанию владельца

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3.2.2 Probe Preparation
The black probe housing contains two Platinum Resistance Thermometers (PRT's) which
are used for measuring the air temperature (called the Dry Bulb temperature) and the
depression temperature (called the Wet Bulb temperature). The Wet Bulb sensor is the one
which is covered by the woven cotton wick. During operation, the wick remains wet by
drawing water (through capillary action) from the reservoir in the bottom of the probe
housing. The reservoir must be filled prior to operation, and drained after operation
allowing the wick to dry. (The probe should never be stored with a wet wick, as a stagnant
wet wick provides an excellent media for the growth of micro-organisms (bacteria), thus
altering the accuracy of the instrument).
Fill the reservoir with pure distilled water by removing the filler plug (the larger of the two
screws) on the bottom plate of the probe housing. A dime usually works well for this
purpose. Using the bottle and dropper provided, fill the reservoir to the bottom of the filling
hole, while holding the probe so that the round white teflon shaft is vertical, and the motor
end is downward. Replace the filler plug and tighten. Squirt several droppers full of water
directly on the wick covering the Wet Bulb sensor. This flooding procedure is used to
clean the wick and flush away possible contaminants. Dry the probe by gently shaking out
excess water from within the teflon shaft portion of the probe. Avoid tapping or banging
the probe. Cotton swab sticks (Q-tips) may be needed to thoroughly dry the inside of the
white teflon probe shaft. Also dry the outside with a clean cloth while watching for leaks
around the bottom of the probe at the edges of the reservoir cover. The reservoir cover is
sealed by a rubber gasket and secured by the small screw in the center. Tighten this center
screw as necessary.
Place the probe in the environment to be tested and connect the white power signal cable. If
multiple probes were calibrated with this 5A-1MP, ensure that the probe number and cable
number match, as they were calibrated from the factory as a set. Connect the other end of
the cable to the mating connector on the 5A-1MP.
3.2.3 System Operation
In order to measure relative humidity and other psychrometric data in the test environment,
the user must
1) Prepare the probe. (Refer to Section 3.2.2).
2) Enter the probe number. (Refer to Section 3.2.4).
3) Enter the current pressure. (Refer to Section 3.2.5).
4) Aspirate the probe. (Refer to Section 3.2.7).
5) Wait approximately 1 minute for stabilization.
6) Display and/or print data. (Refer to Sections 3.2.8, ).
7) Stop probe aspiration. (Refer to Section 3.2.7).
If the psychrometer is being operated within a humidity generator (such as the Thunder
Scientific Model 8500 Automated Two-Pressure Humidity Generator), fittings are available
in order to aspirate the probe from the humidity generator rather than the blower motor.
When using external sources such as this for aspiration, the flow rate of the source must be
known and entered into the 5A-1MP. (Refer to Section 3.2.6, Entering the Flow Rate).