User Guide
Model 412300
A
Current Calibrator
Introduction
Congratulations on your purchase of the Extech Current Calibrator Model 412300
A
. The 412300
A
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.
Meter Description
1.
2.
3.
4.
5.
6.
7.
LCD display
Battery Compartment
AC adaptor jack
Calibration Cable input
Function switch
Neck-strap posts
Keypad
1
7
6
2
4
6
5
3
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412300A-EU-EN v3.4 07/13
Keypad and Switch Descriptions
POWER BUTTON and AUTO POWER OFF FEATURE
1. Use the POWER button to turn the unit ON or OFF. When the unit is powered up, a short self-
test 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
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.
(auto power off activated).
▲▼
INCREASE / DECREASE BUTTONS
Use the
▲ ▼
buttons to increase or decrease the output current value in the source mode.
1.
2.
3.
4.
Press the
▲
button once to increase the value in one digit steps.
Press and hold the
▲
button to increase the value in 10 digit steps.
Press and hold the
▲
button >2 sec and then press the
▼
to increase the value in 100 digit
steps
To decrease the value, use the
▼
button as described above.
ZERO BUTTON
The ZERO button manually zeros the display in the MEASURE mode.
1.
2.
3.
Set the meter to the MEASURE mode
Short the input jack
Press and release the ZERO button
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412300A-EU-EN v3.4 07/13
MEM BUTTON
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.
2.
3.
Select the Source mode as described earlier
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.
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.
2.
3.
As described above, select and display a memory location (M1, 2, 3, 4, or 5)
Use the
▲ ▼
buttons to adjust the display to the desired source value.
Press and hold the MEM button for > 2 seconds. The displayed value will be stored in the
displayed memory location.
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.
2.
Turn the meter on and select the SOURCE mode.
Press and hold the POWER button until
appears in the display and then release the
POWER button. The memory locations will revert to the default values.
Default Memory Values
M1
mA
%
4mA
0%
M2
8mA
25%
M3
12mA
50%
M4
16mA
75%
M5
20mA
100%
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412300A-EU-EN v3.4 07/13
Modes of Operation
MEASURE (Input) Mode of Operation
In this mode, the unit will measure up to 50mADC.
1.
2.
3.
4.
5.
6.
Slide the function switch to the SOURCE/MEASURE position.
Turn the meter ON
Press the MODE button to select MEASURE
Connect the Calibration Cable to the meter.
Connect the Calibration Cable to the device or circuit under test.
Read the measurement on the LCD display.
SOURCE (Output) Mode of Operation
In this mode, the unit can source current up to 24mADC at 1000 ohms
1.
2.
3.
4.
5.
6.
7.
Slide the Mode switch to the SOURCE/MEASURE position
Turn the meter ON
Press the MODE button to select SOURCE
Use the UNIT button to select
%
or
mA
units of measure
Connect the Calibration Cable to the meter
Connect the Calibration Cable to the device or circuit under test
Use the
▲ ▼
buttons to select the desired output value. Use the LCD display to verify the
output level. Alternatively, use the stored calibration values in memory as described in the
MEM button section.
Note
that while the SOURCE display icon is blinking the calibrator is preparing to provide an
output but only after the icon stops blinking will the current actually be sourced.
For the -25% to 125% output range the output is 0 to 24mA. Refer to the Table below.
Display
mA
output
25%
0mA
0%
4mA
25%
8mA
50%
12mA
75%
16mA
100%
20mA
125%
24mA
8.
9.
POWER/MEASURE Mode of Operation
In this mode the unit can measure current up to 24mA and power a 2-wire current loop. The loop
voltage is 24V.
1.
2.
3.
4.
5.
6.
Slide the function switch to the POWER/MEASURE position.
Turn the meter ON
Connect the Calibration Cable to the meter.
Connect the Calibration Cable to the loop. Open the current loop at any convenient location
along the signal path.
Read the measurement on the LCD display.
Use the UNIT button to select % or mA units of measure. In “%” mode the display will read
from -25.0 to +230.0% representing 0.00 to 50.00mA.
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412300A-EU-EN v3.4 07/13
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