THWD3 - Temperature Controller Amprobe - Free user manual and instructions

USER MANUAL THWD3 Amprobe

THWD-3 TH-3 Relative Humidity and Temperature Meters User Manual

Caution! Refer to the explanation in this Manual

Caution! Risk of electric shock Conforms to relevant Australian standards

Complies with European Directives

Power ON / OFF Do not dispose of this product as unsorted municipal waste3 Operating Instructions Power-Up

• Press the key to turn the Humidity/Temperature meter ON or OFF. Selecting Temperature Units When the meter is first powered on, the default scale setting is set to the Celsius (°C ) scale. To change to Fahrenheit (°F) press the button. Press again to revert to Celsius. The next time the meter is turned on, the scale setting will be the same as it was when you powered off last time. Data-Hold Operation The present reading may be held on the display by pressing the button. When the held data is no longer needed, release the data- hold operation by pressing the button again. When the meter is in the Data Hold mode, the , , and buttons are disabled. Relative Operation (TH-3 only) Pressing the button causes the meter to memorize the present reading. The difference between the new reading and the memorized data will be displayed. Press the button again to exit the Relative mode. MIN/MAX Operation Pressing the button places the meter in the MIN/MAX mode. In this mode the maximum value and minimum value is kept in the memory simultaneously and updated with every new data reading. Pressing the button displays the MAX indicator and the Maximum value on the display. Pressing again will display the MIN indicator and the Minimum value on the display. Pressing again causes the MAX and MIN indicators to blink together. This means that these data have been updated in the memory and the reading is the present temperature and humidity. When the meter is in MIN/MAX mode, the and buttons are disabled. To exit MIN/MAX mode, press and hold for two seconds.4 Dew Point and Wet Bulb Temperature (THWD-3 only) Operation The Meter displays ambient temperature when first turned on. To display dew point (DP) temperature, press DP WB once. Press DP WB again to switch to wet bulb (WB) temperature. Pressing DP WB a third time returns the Meter to ambient temperature. The display indicates when dew point and wet bulb temperatures are selected. Auto Power Off By default, when the meter is powered on, it is in the auto power off mode. The meter will power itself off after 30 minutes if no key operation is performed. To disable the auto power off feature, press and hold the button and then power on the meter, The auto power off symbol will disappear to indicate that auto power off is disabled. Low Battery Condition When the battery voltage is under proper operation requirement, the symbol displays on the LCD and the battery needs to be replaced. Wet Bulb Temperature Readings (TH-3) Occasionally the Wet Bulb temperature is required. Use the following procedure and your TH-3 to obtain the wet bulb temperature.

1. Determine RH% condition with the TH-3.

2. Determine temperature (dry-bulb) with the TH-3.

3. Locate dry bulb (DB) temperature line on the Psychrometric chart

(vertical line across the bottom of the chart).

4. Locate relative humidity (RH) line on the chart (curved line across

5. Find the intersection of the DB and RH lines on the chart.

6. Draw a diagonal line, starting at your intersectioin point, until the

Wet Bulb (WB) point is determined. (The wet bulb temperature line is at the outmost curve of the chart). For example, locate the DB temperature of 78 °F on the Psychrometer chart. Locate the RH conditions of 50% RH on the chart. Draw a diagonal line up to the 65 °F WB point.5 Psychrometric Chart Wet Bulb (F)

Humidity Sensor Reconditioning If the unit is found to be out of specification for humidity, the sensor could be offset due to long exposure in a dry environment. This condition is typical of polymer type humidity sensors. The sensor will need to be rehydrated. To rehydrate the sensor, keep it in a 20 °C to 30 °C environment that is >75% RH for at least 12 hours. Recall Factory Calibration Data

1. Turn OFF the meter.

2. Press and hold “°C/°F” and “HOLD” button, then press to power

ON the meter. The display will blink for 3 seconds. While the display is blinking, press “MIN MAX” button to recall factory calibration data.

3. A long beep indicates the meter has reset to factory calibration data.6

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