407026 Datasheet, PDF (6/8 Pages) Extech Instruments Corporation. – Heavy Duty Meter

Data Hold
While measuring, press the HOLD button to freeze the reading. The LCD will display D.H.
indicating that the Data Hold function is engaged. Press HOLD again to return to normal
operation.
Relative % Mode
In the RELATIVE mode of operation, the meter displays light level as a comparison to a
reference value. The reference value is stored by pressing the ‘%’ button while the desired
light level reference is on the display. When the button is pressed, ‘100%’ will be displayed
and the ‘%’ icon will appear.
After the ‘%’ button is pressed, light measurements will be displayed as a percentage of
the reference value. For example, if the light level reference is 1000 LUX, a display of 500
LUX will be represented as 50%. Further, a light level of 250 LUX will display as 25%. Use
the equation below:
Light measurement
Display % = --------------------------------------------------------------------------- X 100
Stored reference light measurement
Press the ‘%’ button again to return to normal operation.
Maximum (MAX), Minimum (MIN), and Average (AVG) readings
The meter can keep track of the highest, lowest, and average readings for later recall.
1. Press the RECORD button to start tracking the MAX, MIN, and AVG readings. The
REC display will switch on.
2. When desired, press the RECALL button.
3. The MAX display icon appears next to the REC display icon. The reading shown is the
highest reading encountered since the RECORD button was pressed.
4. Press RECALL twice more to view the MIN and AVG readings.
5. Press the RECORD button to return to normal operation.
RS-232 PC Interface
This meter is equipped with a RS-232 serial data port. This interface is for use with the
Extech Data Acquisition Software (Part number 407001) and enables the user to capture,
store and display readings on a PC. Contact Extech or refer to the 407001 user manual for
details on the PC interface.
Battery Replacement
When the low battery indicator appears (LBT), replace the battery as soon as possible.
Reliable readings can be obtained for several hours after the first appearance of the low
battery indication. To replace the battery:
1. Remover the meter's rubber protective holster.
2. The battery compartment is located on the lower back of the meter. Pry the battery
compartment cover off using a small coin or screwdriver and remove the battery.
3. Replace the 9V battery and reinstall the cover.
4. Ensure that the battery cover is secured after replacing the battery.
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Model 407026 Version 2.3 January 2004