Operation - Extech Instruments 421504 Instruction Manual

5. OPERATION

5.1 Getting Started
First ensure that a fresh battery is installed then plug the RTDs into the meter's RTD
input terminals.
5.2 Powering the Meter
Press the "Power" key to toggle the meter ON/OFF.
NOTE: If the SET, RELATIVE, or MIN/MAX/AVG MODE is
engaged, the meter cannot be powered down. Exit these modes
before attempting to power down.
5.3 Temperature Units
The Main and Second display (one for each RTD input) can each read in either C or F.
Press the appropriate "C/F" key to toggle between C and F temperature units. The
meter remembers the desired units of measure upon power OFF.
5.4 Data Hold Mode
While the meter is measuring, pressing the "Hold" key "freezes" the MAIN DISPLAY
temperature value. When selected, the "HOLD" indicator will appear on the LCD. Press
"Hold" again to cancel this operation. In MIN/MAX Mode, pressing the "Hold" key
cancels the data recording session (press "Hold" again to resume recording).
5.5 Main Display Input Selection "T1, T2, or T1 - T2"
Pressing the "T1 T2 / T1 - T2" key (the key with the number 4 overlay) permits the user
to select the RTD input configuration which will be reflected on the meter's Main Display
(largest LCD digits). Choose "T1 or T2" to show either RTD input 1 or 2 respectively.
Select "T1 - T2" to display the difference between the two RTD input temperatures. In
T1 - T2 mode, a reading of zero indicates that both RTDs are sensing the same
temperature. Use the "Pt385/3926" key to select RTD type.
5.6 "Pt385/3926" #1 Input (T1) - RTD Type Selection for the Main Display
Match the Alpha RTD type (3850 or 3926) that is connected to the T1 terminal by
toggling the "Pt385/3926" key. The meter remembers this selection upon power OFF.
5.7 MIN/MAX/AVG RECORD Mode (for Main Display only
To enter this mode, press the "MIN/MAX" key (the RECORD display icon will appear).
Repeated key-presses cycle through Min, Max, and Avg modes each with its own LCD
icon. Once this key is pressed, the meter begins recording peak, valley, and average
temperatures. Each time a new peak is measured, the previous Max displayed value is
replaced. The same applies to the Min function. An audible beep alerts the user that a
new peak or valley has been recorded. To toggle between start/stop recording, press
the HOLD key. When recording is stopped, the stored values are held in meter memory
until Min/Max/Avg mode is canceled or resumed by pressing the "Hold" again.
The Avg mode keeps a true running average of temperatures recorded since the
"MIN/MAX" key was first pressed (up to a maximum of 22 hours). If 22 hours elapse the
average stored at this point is held on the display and is no longer updated (the MIN and
MAX functions continue without interruption indefinitely). If an overload is recorded, the
Avg function is halted and the Avg. display shows "-------".
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4 421504 Ver. 1.8 01/03