Congratulations on your purchase of the Extech Current Calibrator Model 412300A. The 412300A
can measure/source current and can also power a current loop. A built-in five location memory
can store customized calibration current output steps. The Oyster Series meters have a
convenient flip up display with neck-strap for hands-free operation. This meter is shipped fully
tested and calibrated and, with proper use, will provide years of reliable service.
1. Use the POWER button to turn the unit ON or OFF. When the unit is powered up, a short selftest will ensue after which the display will stabilize.
2. This meter can either be powered by one 9V battery or an AC adapter.
3. When the battery symbol appears on the LCD display, replace the battery as soon as possible.
Low battery power may cause inaccurate readings and erratic meter operation.
4. This instrument is equipped with Auto Power OFF which turns the meter off after 10 minutes of
inactivity. To override this feature; press and hold the MODE button until the display shows
(auto power off de-activated) or (auto power off activated).
FUNCTION SLIDE SWITCH
1. Slide the Function switch on the side of the meter to the desired function (Source/Measure or
Power/Measure).
2. In the Source/Measure position the meter can be used to generate current or measure current
(MODE button is used to choose Source or Measure).
3. In the Power/Measure position, the meter can power a current loop with 24Vdc and, at the same
time, measure the current.
MODE BUTTON
Press the MODE button to select either SOURCE (output) or MEASURE (input). This applies when
the Function switch is set to Source/Measure.
UNIT BUTTON
Press the UNIT button to select mA or % units.
▲▼ INCREASE / DECREASEBUTTONS
▲ ▼buttons to increase or decrease the output current value in the source mode.
Use the
1. Press the
2. Press and hold the
3. Press and hold the
steps
4. To decrease the value, use the
ZERO BUTTON
The ZERO button manually zeros the display in the MEASURE mode.
1. Set the meter to the MEASURE mode
2. Short the input jack
3. Press and release the ZERO button
▲ button once to increase the value in one digit steps.
▲ button to increase the value in 10 digit steps.
▲ button >2 sec and then press the ▼ to increase the value in 100 digit
The memory feature provides the user with five (5) user programmable source values for stepped
calibration outputs. The feature is available for mA and % units in the SOURCE mode. The stored
values are kept in non-volatile memory (memory that is retained even after power is removed from
the calibrator).
Source from the stored memory values:
1. Select the Source mode as described earlier
2. Press the MEM button. The M1 icon (memory location 1) will appear in the display and the
value stored in that location will be displayed and sourced.
3. Repeated pressing of the MEM button will step through the 5 memory locations.
NOTE: The “SOURCE” icon will blink when the output value has not reached a stable level.
The common cause for the “SOURCE” icon to remain blinking is that the load impedance is
too high in the current mode.
Storing values into memory:
1. As described above, select and display a memory location (M1, 2, 3, 4, or 5)
2. Use the
3. Press and hold the MEM button for > 2 seconds. The displayed value will be stored in the
Default memory values.
Five common source values are permanently programmed in memory as the default values.
These values can be replaced by user selected values.
To reset the meter to the default memory values:
1. Turn the meter on and select the SOURCE mode.
2. Press and hold the POWER button until appears in the display and then release the
▲ ▼buttons to adjust the display to the desired source value.
displayed memory location.
POWER button. The memory locations will revert to the default values.
Display 9999 count LCD
Meter Power 9 volt battery or AC adaptor
Auto Power OFF Meter automatically powers off after 10 minutes of inactivity
Current output capability 24mADC at 1000 ohms
Operating Temperature 5ºC to 40ºC (41ºF to 104ºF)
Storage Temperature -20
Operating Humidity Max 80% up to 31ºC (87ºF) decreasing linearly to 50% at 40ºC
Storage Humidity <80%
Operating Altitude 2000meters (7000ft.) maximum
Dimensions 96 x 118 x 45mm (3.8 x 4.7 x 1.8") folded
Weight 340g (12 oz.)
Accessories Supplied 9V battery, AC Adaptor and calibration cable with spade lugs
Range Specifications
Mode Function Range (Resolution) Accuracy (% of reading
Measure Current 0 to 50mA (0.01mA)
Percent (%) -25% to +230% (0.1%)
Source Current 0 to 24mA (0.01mA)
Percent (%) -25% to +125% (0.1%)
Power Loop Power 24VDC, <50mA
o
C to 60oC (- 4oF to 140oF)
(104ºF)
± (0.075% + 1 digit) or ± 3 digits
(whichever is greater)
Battery Replacement
When the battery symbol appears on the LCD, replace the 9V battery as soon as possible.
1. Open the calibrator’s lid as far as possible.
2. With a coin or wide blade screwdriver, open the battery compartment moving in the direction
of the arrow embossed on the compartment cover (location of compartment is identified in
the meter description section).
3. Replace the battery and close the battery compartment cover.
You, as the end user, are legally bound (Battery ordinance) to return all used batteries
and accumulators; disposal in the household garbage is prohibited!
You can hand over your used batteries / accumulators at collection points in your
community or wherever batteries / accumulators are sold!
Disposal: Follow the valid legal stipulations in respect of the disposal of the device at the
end of its lifecycle