Extech Instruments Corporation, 285 Bear Hill Road, Waltham, MA 02451
Page 3 PRC70-EN-V2.1 12/11
4 Safety Information
For the correct and safe use of the instrument, be sure to follow the cautionary notes stated in this manual whenever
handling the instrument. Extech Instruments shall not be held liable for any damage resulting from use of the instrument in a
manner other than prescribed in the cautionary notes.
Warning identifies conditions and actions that pose hazards to the user; a Caution identifies conditions and actions that
A
may damage the meter or the equipment under test.
Refer to Table 2 for the international electric symbols adopted by the calibrator.
Table 2 - International Electrical Symbols
EARTH GROUND
Warning
To avoid possible electric shock or personal injury:
zDo not apply more than the rated voltage, as marked on the calibrator, between terminals or between any terminal and
earth ground;
z Before use, verify the meter’s operation by measuring a known voltage;
z Follow all equipment safety procedures;
z Do not connect the probe of the test leads with any live power when the other end has been inserted into the current
jack;
zDo not use the meter if it is damaged. Before using the meter, inspect the case. Look for cracks or missing plastic. Pay
particular attention to the insulation surrounding the connectors;
z Select the proper function and range for the measurement;
z Make sure the battery door is closed and latched before operating the meter;
z Remove test leads from the meter before opening the battery door;
z Inspect the test leads for damaged insulation or exposed metal. Check test lead continuity. Replace damaged test leads
before using the meter;
z When using the probes, keep fingers behind the finger guards on the probes;
z Connect the common test lead before connecting the live test lead. When disconnecting test leads, disconnect the live
test lead first;
z Do not use the meter if it operates abnormally. Protection may be impaired. When in doubt, have the meter inspected;
z Do not operate this instrument in areas where inflammable or explosive gases or vapor exists. It is extremely hazardous
to use the instrument under such environments;
z Do not operate the meter near explosive gas, vapor, or dust;
z Use only four (4) AAA 1.5V batteries, properly installed in the meter case, to power the meter;
z Disconnect the test leads before shifting to different source or measurement functions;
z When servicing the meter, use only specified replacement parts.
z To avoid false readings, which could lead to possible electric shock or personal injury, replace the batteries as soon as
the low battery indicator (
) appears.
WARNING
INFORMATION
Caution
To avoid possible damage to meter or to equipment under test:
z Disconnect the power and discharge all high-voltage capacitors before testing resistance or continuity.
z Use the proper jacks, functions, and ranges for the measurement or source operation.
Page 4 PRC70-EN-V2.1 12/11
5 Calibrator Description
Refer to Figure 1
1. LCD display
2. Digit up/down adjust buttons
3. Control keypad
4. Measurement terminals
5. Source terminals
2
4
Figure 1 – Meter Description
5.1 Measurement/ Source Terminals
Figure 2 shows the calibrator’s measurement /source terminals. Table 3 explains their use.
Figure 2 - Measurement/ Source Terminals
Table 3 - Measurement/ Source Terminals
1
3
5
Terminal Function
1
2
3
4
5
6
7
8
Common (COM) return(-)terminal for all
measurement functions
Measurement Signals(+):DCV, OHM, FREQ,
TC, RTD, SWITCH, and CONT (continuity)
Measurement Signal(+):mADC
3W Terminal:measurement terminal of the 3W
OHM, RTD
LOOP Terminal:+24VDC Loop Power Terminal
Source Signal:(+)DCmA
Source Signals:(-)OHM、RTD
Common (COM) return(-)terminal for source
functions
Source Signal(+)DCV, OHM, TC, RTD, XMT,
FREQ, CYC, and SWITCH
Source Signal:(-)mADC
Page 5 PRC70-EN-V2.1 12/11
5.2 Keys
Figure 3 lists the calibrator’s function keys and Table 4 explains their use.
Figure 3 – Calibrator Function Keys
Table 4 – Function Key Descriptions
No. Name Function
1~5 Source value set key Increment source set point
6~10 Source value set key Decrement source set point
11
12
13 Power key Switch the power ON or OFF
14 Backlight Switch the backlight ON or OFF
15
16
17
18
19
20
21
22
23
24
25
26
Measurement ON key
Source ON key
Measurement FUNC Key
Source FUNC Key
TEMP Key
ZERO Key
Measurement RANGE Key
Source RANGE Key
AVG Key
25/100% key
HOLD Key
START Key
LOOP Key
Key
Switch measurement functions ON or OFF
Switch source function ON or OFF
Select measurement function
Select source function
Switch room temperature monitoring function ON or OFF
In TC source or measurement mode, switch the RJ compensation ON/OFF
Set the source value to zero-point; In pulse source function, set the pulse number.
Select measurement range; Measurement mA and percentage shifting.
Select source range; Source mA and percentage shifting.
Measuring average value
In mA source function, select 25% or 100% manual step output mode.
In pulse number, frequency or switch source, set the frequency value.
Freeze measured value
Source auto-pulse number, switch ON mA auto-stepping or sweeping function.
Convert sourced TC temperature and mV, and sourced RTD temperature and Ohms.
24v Loop circuit power: Convert the measured TC temperature and the mV, the
measured RTD temperature and the Ohms.
In DCmA source mode, select auto-wave; In frequency/pulse source mode, set
amplitude
Page 6 PRC70-EN-V2.1 12/11
5.3 Display Screen
a. Battery level indicator
b. Measure Mode icon
c. Measurement function ON
d. Measurement function OFF
e. Average value for measurement
f. Display HOLD for measured value
g. Switch measurement
h. Room temperature measurement
i. Beeper for measurement continuity
j. Measured value
k. Unit of measure
l. Dividing line between measurement and source mode displays
m. Type of RTD measurement / source
n. Dividing line between measurement and source mode displays
o. Type of Thermocouple (TC) measurement / source
p. Reference Junction Compensation ON
q. 24V Loop Power Supply ON
r. Source Mode icon
s. Source function ON
t. Source function OFF
u. Set -point for source
v. RUN icon for auto-step and auto-sweep
w. Unit of measure for setpoint of source
x. Not used
y. Not used
m
Figure 4 - LCD display
cd e
g
f
h
a
b
I
j
x
l
n
r
s
k
o
q
p
w
t
u
y
v
Page 7 PRC70-EN-V2.1 12/11
6 Source/Measurement Preparations
Precautions for Safe Use of the Instrument
zWhen using the instrument for the first time, be sure to read the instructions given in Section 4 “Precautions for Safe
Use of the Instrument.”
z Do not open the instrument’s case. Contact the vendor for service.
z In case of failure: Should the instrument begin to emit smoke, give off an unusual odor, or show any other anomaly,
immediately switch OFF the POWER. If using an AC Charger, disconnect the plug from the wall outlet. Also switch OFF
power to the object under test that is connected to the input terminals. Contact the vendor.
zCharger: Use an AC Charger dedicated to the instrument. Avoid placing any load on the Charger; prevent any heat-
emitting object from coming into contact with the adapter.
General Handling Precautions
zBefore transporting the instrument, switch OFF power to the object under test, and then power off the meter. When
using an AC Charger, disconnect the power cord from the wall outlet. Finally, detach all lead cables from the instrument.
Use a dedicated carry case when transporting the instrument.
z Do not bring any electrified object close to the input terminals, since this may damage the internal circuitry.
z Do not apply any volatile chemical to the instrument’s case or operation panel. Do not leave the instrument in contact
with any product made of rubber or vinyl for a prolonged period. Be careful not to let a soldering iron or any other heat-
emitting object come into contact with the operation panel (panel is made of thermoplastic resin).
zBefore cleaning the instrument’s case or operation panel, disconnect the power cord plug from the wall outlet if using an
AC Charger. Use a soft, damp cloth to gently wipe the outer surfaces of the instrument. Water that is allowed into the
instrument can result in malfunction.
z If using an AC Charger, disconnect the power cord plug from the wall outlet when the meter is not in use.
z For handling precautions regarding the batteries, see “Installing or Replacing the Batteries”.
z Never use the instrument with the cover of the battery holder opened.
Environmental Requirements
Use the instrument in locations that meet the following environmental requirements:
zAmbient temperature and humidity:
o
Ambient temperature range: 32 to 122
F (0 to 50oC); ambient humidity range: 30 to 80% RH; non-condensing.
zPlace the instrument on flat and level areas
Do not use the instrument in locations that are:
z Exposed to direct sunlight or close to any heat source.
z Exposed to frequent mechanical vibration.
z Close to an electrical noise source, such as high-voltage equipment or motive power sources.
z Close to any source of intensive electric or electromagnetic fields.
z Exposed to large amounts of grease fumes, hot steam, dust or corrosive gases.
z Exposed to unstable areas such as where a risk of explosion due to the presence of flammable gases exists.
Notes:
zUse the instrument under the following environmental conditions when precise measurements are required:
o
Ambient temperature range: 74
zWhen using the instrument within a temperature range of 32 to 64
F (23oC) ±5o; ambient humidity range: 20 to 80% RH (non-condensing)
o
F (0 to 18oC) or 82 to 122oF (28 to 50oC), add a value
based on the temperature coefficient shown in the “Specifications” section to the given accuracy rating.
zWhen using the instrument at an ambient humidity of 30% or lower, prevent electrostatic charges from being produced
by using an antistatic mat or other alternative means.
Page 8 PRC70-EN-V2.1 12/11
zCondensation may occur if the instrument is relocated from places with low temperature and humidity to places with
high temperature and humidity, or if the instrument experiences a sudden temperature change. In these cases, leave
the instrument under the given ambient temperature for at least one hour to ensure that the instrument is free from
condensation before using the instrument.
Indication of Battery Level
The battery replacement indicator shows the battery level in five steps according to the measured voltage of the batteries.
Full battery:
The battery level is below 50% full:
The battery level is below 25% full:
Low battery:
The battery icon flashes in sequence when charging.
Note that the battery replacement indicator is driven by directly measuring the battery voltage when the calibrator is in actual
operation. Consequently, the indicator may read differently depending on the battery load condition (e.g., the load condition
of the source output or on/off state of the measurement function).
Replace the batteries and fuses as described in the section “Replacing or installing batteries and fuses” toward the end of
this User Guide.
Connecting the Charger
Warning
zMake sure the voltage of the AC power source matches the rated supply voltage of the Charger before connecting the
Charger to the AC power source.
z Do not use a Charger other than the dedicated, supplied Charger.
z Do not charge non Ni-Cd, Ni-MH batteries.
Step 1: Ensure that the calibrator is OFF.
Step 2: Insert the plug of the optional Charger into the Charger connection jack.
Notes:
z Switch OFF the calibrator before connecting or disconnecting the Charger from AC power.
z Unplug the Charger from the Charger connection jack of the calibrator when discharging.
z Do not charge the calibrator without batteries installed.
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Switching Power ON
Press the power key once to switch ON the calibrator. Press and hold the power key for 2 seconds to switch OFF the
calibrator.
Switching MEASURE Mode ON and OFF
The measurement function defaults to the OFF state each time the calibrator is switched ON.
z Use the MEASURE (ON) key to switch the MEASURE mode ON/OFF.
z If the MEASURE function is not needed and therefore switched OFF, power to the measurement circuit is also switched
OFF within the calibrator. Thus, battery power is saved.
zTurning off the MEASURE function causes the on-screen measured value to switch off and the “OFF” indicator to
appear.
zTo resume measurement when the MEASURE function is off, press the MEASURE (ON) key again.
Automatic Power OFF
When the calibrator is running on battery power, and no key is pressed for approximately ten minutes, the calibrator switches
OFF automatically. The automatic power-off time can be programmed or set to the factory default state, see the
“Programming the Global Settings” section.
Switching the LCD Backlight ON and OFF
Press the backlight key to switch ON the backlight; press again to switch it OFF. Battery life is shortened by backlight
overuse.
Notes: The backlight automatically switches OFF after 30 seconds. The time can be programmed or reset to the factory
default condition, see the “Programming the Global Settings” section.
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7.3.1 Manually Set 25%, 100% 4–20 mA Function
The source can be set within the 4–20 mA current range.
Step 1: In DC current mode, press the〔25%100%〕key to display “25%SET” on the lower part of the screen, and press
again to display “100%SET”. The default source values will be shown.
Step 2: Using each pair of 〔S〕/〔T〕output setting keys, set the signal in a step-by-step manner. In the 25% set point
condition, the signal can be set in 4 mA increments or decrements in the sequential order 4-8-12-16-20 by each press of the
key. In the 100% set point condition, the signal can set in 16 mA increments or decrements by each press of the key.
Pressing the (ZERO) key initializes the signal set point to the default value (4.00).
Step 3: Pressing the (ON) key causes the indicator on the LCD to change from ‘’OFF‘’ to ‘’ON ‘’. The calibrator sources the
preset 4–20 mA current signal between the output terminals.
Step 4: To switch OFF the output, press the (ON) key again. The’’ OFF ‘’appears on the LCD and no signals are sourced
between the terminals.
6.3.2 Auto-stepping and auto-sweeping 4-20mA function
The user can set a 4–20 mA range in which to auto-step or auto-sweep. 80 seconds are required to finish a 4-20mA cycle in
auto-sweeping mode and 20 seconds are required for auto-stepping mode.
Step 1: In the DC current mode, press the 〔
the screen; press again to display the auto-sweeping mode icon “
〕key to display the auto-stepping mode icon “” on the lower part of
”. The default source value will display.
Step 2: Pressing the (ON) key causes the indicator on the LCD to change from ‘’OFF‘’ to ‘’ON ‘’. The calibrator sources the
default 4–20 mA current signal between the output terminals.
Step 3: Pressing the (START) key starts the auto-stepping or the auto-sweeping mode. The “RUN” icon is displayed in the
lower part of the LCD.
Step 4: Pressing the (START) key again stops the auto-stepping or the auto-sweeping mode. The “RUN” icon switches
OFF.
Step 5: Pressing the (ON) key cancels the sourcing and the ‘’OFF’’ icon is displayed on the screen. No signals are sourced
between the terminals.
Notes:
z Press the (START) key again to continue the auto-stepping or the auto-sweeping mode after stopping them; The “RUN”
icon is displayed on the lower part of the screen.
z The ability to use the (START) key to start mA auto-stepping and auto-sweeping mode is only available when the
source function is in the ON state.
z Starting the mA auto-sweeping mode switches OFF the measurement mode. The mA auto-stepping mode and the
measurement function cannot run simultaneously.
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7.5.1 Temperature (TC) Monitor Function
The calibrator offers a temperature monitor function convenient for observing the voltage value sourced between the output
terminals in TC source mode. In the TC source mode, press the (START) key and the LCD will show the voltage value
sourced between the output terminals (this value varies in response to the changes of the reference junction compensation).
Press the (START) key again and the LCD will show the preset temperature value.
7.6 Sourcing RTD Temperature
zFirst, the calibrator sources a resistance signal by receiving the resistance-measuring current (I) supplied from the
device being calibrated (such as a resistance meter) and then delivering the voltage (V) proportional to the preset
resistance (R) between the output terminals, and thus producing the equivalent resistance R =V/I. Consequently, the
calibrator sources the signal correctly only for such devices that employ this method of measurement.
zThe allowable range of the resistance measuring current that the calibrator receives from a resistance measuring device
under calibration is rated as 0.1 to 3 mA. To ensure accuracy, the resistance measuring current from the device under
calibration is strictly confined within this range. For further details, see the “Specifications” section.
zSourced resistance signals do not include the resistance component of the lead cables. The entire resistance, when
measured at the ends of the lead cables for sourcing, is given by adding the resistance of the lead cables
(approximately 0.1 ohms) to the sourced resistance signal. For the sourcing of precise resistance signals, use three-wire
or four-wire connections.
Step 1: Using the function key (FUNC), select the RTD function. Using the (RANGE) key, select a RTD range (PT100,
PT200, PT500, PT1000, Cu10, Cu50). The selected function, the default range source value, and the unit of measure are
shown in the lower area of the LCD.
Step 2: Set the output value digit by digit using each pair of〔S〕/〔T〕keys.
Each press of the〔S〕/〔T〕key increases or decreases the digit. Increasing the digit from 9 or decreasing it from 0
causes the digit to overflow or underflow, allowing the output value to be set without interruption. Holding down the〔S〕/〔
T〕key changes the digit in question quickly. And the value won’t change if it is increased or decreased to the Maximum or
Minimum value. Pressing the (ZERO) key initializes the output set point to the default value (0).
Step 3: Pressing the (ON) key causes the SOURCE indicator on the LCD to change from ‘’OFF‘’ to ‘’ON ‘’. The calibrator
sources the preset resistance value between the output terminals.
Step 4: To switch OFF the output, press (ON) again. The ‘’OFF‘’ icon appears on the LCD and no signals are sourced
between the terminals. The connection methods based on three-wire and four-wire are shown in Figure 9.
Note: The RTD source function is unavailable if the TC /RTD measurement function is ON.
7.6.1 Temperature Monitor Function
The calibrator offers a temperature monitor function for easily observing the resistance value sourced between the output
terminals. In the RTD source mode, press the (START) key and the LCD will show the resistance value sourced between the
output terminals. Press (START) again and the LCD will show the preset temperature value.
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7.7 Sourcing Frequency
The calibrator can source a constant pulse signal according to the preset frequency and amplitude.
Step 1: Using the function selector switch (FUNC), select the frequency source function. The LCD shows the default
frequency value (10 Hz) and the frequency symbol
Step 2: Using the (RANGE) key, select a frequency range (100Hz, 1KHz, 10Hz, 100KHz). The selected function, the default
range source value, and the unit of measure are shown in the lower area of the LCD.
Step 3: Set the output value digit by digit using each pair of〔S〕/〔T〕output setting keys.
Each pair of〔S〕/〔T〕keys corresponds to each digit of the LCD reading. Each press of the〔S〕/〔T〕key increases
or decreases the digit. Increasing the digit from 9 or decreasing it from 0 causes the digit to overflow or underflow, allowing
the output value to be set without interruption. Holding down the〔S〕/〔T〕key changes the digit quickly. The value won’t
change if it is increased or decreased to the Maximum or Minimum value.
Step 4: Pressing the〔VPEAK〕key once switches to the amplitude setting mode. The LCD shows a reading of 1V.
Step 5: Set the output value digit by digit using each pair of〔S〕/〔T〕output setting keys.
Each pair of〔S〕/〔T〕keys corresponds to each digit of the LCD reading. Each press of the〔S〕/〔T〕key increases
or decreases the digit. Increasing the digit from 9 or decreasing it from 0 causes the digit to overflow or underflow, allowing
the output value to be set without interruption. Holding down the〔S〕/〔T〕key changes the digit quickly. The value won’t
change if it is increased or decreased to the Maximum or Minimum value.
Step 6: To re-enter the frequency set mode and set the frequency, press the〔FREQ〕key.
Step 7: Pressing the (ON) key causes the SOURCE indicator on the LCD to change from ‘’OFF‘’ to ‘’ON ‘’. The calibrator
sources constant pulse signals between its output terminals according to preset frequency and amplitude.
Step 8: To switch OFF the output, press the (ON) key again. The ‘’OFF‘’ icon appears on the LCD and no signals are
sourced between the terminals.
in the lower LCD area.
7.8 Sourcing a Number of Pulses
The calibrator can source a preset number of pulse signal according to the preset frequency and amplitude.
Step 1: Using the function selector switch (FUNC), select the pulse source function. The LCD shows the default value (10
Hz) and the pulse icon
Step 2: Using the (RANGE) key, select a frequency range. The selected function, the default range source value, and the
unit of measure are shown in the lower portion of the LCD.
Step 3: Set the output value digit by digit using each pair of〔S〕/〔T〕output setting keys.
Each pair of〔S〕/〔T〕keys corresponds to each digit of the LCD reading. Each press of the〔S〕/〔T〕key increases
or decreases the digit. Increasing the digit from 9 or decreasing it from 0 causes the digit to overflow or underflow, allowing
the output value to be set without interruption. Holding down the〔S〕/〔T〕key changes the digit quickly. The value won’t
change if it is increased or decreased to the Maximum or Minimum value.
.
Page 17 PRC70-EN-V2.1 12/11
Step 4: Pressing the〔VPEAK〕key once switches to the amplitude setting mode. The LCD shows a reading of 1V.
Step 5: Set the output value digit by digit using each pair of 〔S〕/〔T〕output setting keys.
Each pair of〔S〕/〔T〕keys corresponds to each digit of the LCD reading. Each press of the〔S〕/〔T〕key increases
or decreases the digit. Increasing the digit from 9 or decreasing it from 0 causes the digit to overflow or underflow, allowing
the output value to be set without interruption. Holding down the〔S〕/〔T〕key changes the digit quickly. The value won’t
change if it is increased or decreased to the Maximum or Minimum value.
Step 6: Press the (CYC) key to enter the pulse number set mode; the LCD will show the default value (1 CYC).
Step 7: Set the output value digit by digit using each pair of〔S〕/〔T〕output setting keys.
Each pair of〔S〕/〔T〕keys corresponds to each digit of the LCD reading. Each press of the〔S〕/〔T〕key increases
or decreases the digit. Increasing the digit from 9 or decreasing it from 0 causes the digit to overflow or underflow, allowing
the output value to be set without interruption. Holding down the〔S〕/〔T〕key changes the digit quickly. The value won’t
change if it is increased or decreased to the Maximum or Minimum value.
Step 8: To re-enter the frequency set mode, press the〔
FREQ〕key.
Step 9: Pressing the (ON) key causes the SOURCE indicator on the LCD to change from ‘’OFF‘’ to ‘’ON ‘’, and the
calibrator sources low level signals between its output terminals.
Step 10: Press the (START) key to allow the calibrator to source the set number of pulses according to the preset frequency
and amplitude, the LCD will show the “RUN” icon.
Step 11: When source is complete, the calibrator automatically switches the output OFF and ceases operation. The “RUN”
symbol also switches OFF.
Step 12: To switch OFF the output manually, press the (ON) key again. The ‘’OFF‘’ icon appears on the LCD and no signals
will be sourced between the terminals.
Notes:
z The frequency range of the pulse can only be changed by pressing (RANGE) in the frequency set mode.
z When the “RUN” symbol switches OFF, the user can change the frequency and amplitude when the source function is
in ‘’ON ‘’ or ‘’OFF‘’.
zDuring the pulse sourcing process, pressing the (START) key causes the calibrator to switch the output OFF; the “RUN”
icon switches OFF also. Press the (START) key again to restart the sourcing function.
zRestarting the pulse output requires that the source function be in the ‘’ON ‘’state.
Page 18 PRC70-EN-V2.1 12/11
7.9 Sourcing Contact Output
Switch the output terminals ON or OFF using the contact output function. The contact-switching device is an FET.
Step 1: Using the function key (FUNC), select the contact output source function. The LCD shows the default value (10Hz)
and the “
Step 2: Using the (RANGE) key, select a frequency (100Hz, 1KHz, 10 KHz, 100KHz).
Step 3: Set the output value digit by digit using each pair of〔S〕/〔T〕output setting keys.
Each pair of〔S〕/〔T〕keys corresponds to each digit of the LCD reading. Each press of the〔S〕/〔T〕key increases
or decreases the digit. Increasing the digit from 9 or decreasing it from 0 causes the digit to overflow or underflow, allowing
the output value to be set without interruption. Holding down the〔S〕/〔T〕key changes the digit quickly. The value won’t
change if it is increased or decreased to the Maximum or Minimum value.
Step 4: Pressing the (ON) key causes the SOURCE indicator on the LCD to change from ‘’OFF‘’ to ‘’ON ‘’.
Step 5: To switch the output OFF, press the (ON) key again. The ‘’OFF‘’ icon appears on the LCD and signals sourced
between its terminals will be switched OFF.
Notes:
z The contact output source function is unavailable if the frequency measurement function is ON.
z The amplitude and pulse number cannot be set when in the contact output mode.
z The contact output is polarized. Generally, connect the positive polarity with the high (H) jack of the calibrator and the
negative polarity with the low (L) jack.
zNote that the maximum allowable current for the contact output is 50mA.
“ switch symbol.
7.10 Zero-off function
For any DC voltage, DC current, Resistance (ohms), TC (thermocouple) or RTD range, pressing the (ZERO) key initializes
the preset source value.
In the frequency, pulse, and contact output modes, the (ZERO) key is unavailable.
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Warning
z Before connecting the calibrator to the device under test, switch OFF the power to the device.
z Do not apply voltage or current exceeding the allowable voltage (60 V) or current (55 mA). Exceeding the limits will
endanger instrument and also create a risk of personal injury due to electrical shock.
zMistaking the H voltage input terminal for the mA current input terminal, and vice versa, when wiring, is extremely
dangerous. Take great care in making connections and always double check the accuracy of the connection
configuration.
zThe current input terminals are equipped with a built-in current input protection fuse. Over-current input to the terminals
will cause the fuse to blow. If the fuse is blown, replace it following specified ratings. For details on fuse replacement,
see the “Replacing the battery and fuse” section.
Warning
Wiring or operational errors can lead to damage to the instrument and personal injury due to electrical shock. Exercise the
utmost care when carrying out the measurement tasks.
8.2 Measuring DC Voltage
Step 1: Ensure that the test lead cables are not connected to the instrument or device under test.
Step 2: Using the function key (FUNC), select the DC Voltage measurement function.
Step 3: Connect the test lead cables to the terminals of the instrument under test.
Step 4: Using the (RANGE) key, select a range from 50mV, 500mV, 5V, 50V. The selected function, the measured value,
and the unit of measure are shown in the upper area of the LCD.
8.3 Measuring DC Current
Step 1: Ensure that the test lead cables are not connected to the instrument or device under test.
Step 2: Using the function key (FUNC), select the DC Current measurement function.
Step 3: Connect the test lead cables to the measuring terminals of the instrument under test.
Step 4: The selected function, the measured value, and the unit of measure are shown in the upper area of the LCD.
87.3.1 mA % Display
In the mA measurement mode, pressing the (RANGE) key converts the measured value to the mA% mode (shown on
the upper area of the LCD). See the equation below.
100 (current measured value mA-4mA)
mA %= %
16 mA
Press the
(RANGE) key again to return to the measured value, shown on the upper area of the LCD.
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junction compensation stabilizes.
8.5.1 Using the RJ sensor
Use the RJ-ON key to turn the Resistance Junction Temperature compensation ON or OFF. With the temperature
compensation ON, the display will show the RJ-ON icon and the internal temperature (top right of the LCD).
8.5.2 Temperature Monitor Function
The calibrator offers a temperature monitoring function to observe the voltage value measured from the input terminals. In
the TC measurement mode, pressing the (T.DISPLAY) key shows the voltage value measured. Pressing the key again
shows the measured temperature value.
8.6 Measuring Temperature with an RTD
Step 1: Ensure that the test lead cables are not connected to the instrument under test.
Step 2: Using the function key (FUNC), select the RTD measurement function.
Step 3: Connect the test lead cables to the terminals of the instrument under test as shown in Figure 14.
Step 4: Using the measurement (RANGE) key, select the desired range from PT100, PT200, PT500, PT1000, Cu10, and
C50.The selected function, the default measured value, and the unit of measure are displayed.
Notes:
z The RTD measurement function is unavailable if the TC /RTD source function is ON.
z The calibrator defaults to the 3-wire connection method when measuring RTD. When using the 2-wire connection
method, pay special attention to linking (shorting) the “COM” and “LOOP” terminals.
7.6.1 Temperature Monitor Function
The calibrator offers a temperature monitoring function to observe the resistance value measured from the input terminals. In
the TC measurement mode, pressing the (T.DISPLAY) key shows the resistance value measured from the input terminals.
Pressing the key again shows the measured temperature value.
8.7 Measuring Frequency
Step 1: Ensure that the test lead cables are not connected to the instrument under test.
Step 2: Using the function key (FUNC), select the frequency measurement function.
Step 3: Connect the test lead cables to the measuring terminals of the instrument under test.
Step 4: Using the measurement (RANGE) key, select the suitable range (500Hz, 5KHz, 50KHz).The selected function, the
measured value, and the unit of measure are shown in the upper part of the LCD.
Note: The frequency measurement function is unavailable if the frequency, pulse, contact or pressure source function is ON.
Page 24 PRC70-EN-V2.1 12/11
8.8 Measuring switch
The calibrator can measure the opening and closing of a dry contact switch. Using the function key (FUNC), select the switch
measurement function. The LCD displays the switch symbol
second if the state of the switch changes (opens or closes).
”on the upper area. The beeper sounds for one
8.9 Measuring Continuity
Continuity measurements are used to detect the completeness of a circuit or wire (e.g. a resistance smaller than 50 ohms).
Using the function selector switch (FUNC), select the continuity measurement function. The LCD displays the continuity
symbol “
loop circuit resistance is smaller than 50Ω; The LCD shows the measured resistance.
”on the upper area. Connect the devices as shown in Figure 11, and the beeper will sound continuously if the
8.10 Measurement-filtering function
Selecting the measurement-filtering function stabilizes the measured value displayed on the LCD. In the DCV, DCmA, OHM,
TC, RTD modes pressing (AVG) key causes a calculation for the average of the samples. The LCD shows the “AVG”
symbol. Pressing the (AVG) key again cancels the calculation and the “AVG” symbol switches OFF.
8.11 Measured Value HOLD function
Apart from the continuity and switch measurement functions, the HOLD function can be used to freeze the measured value
on the upper part of LCD. Pressing the (HOLD) key activates the HOLD mode, and the LCD displays the “HOLD” symbol. To
exit HOLD mode, press the (HOLD) key again; the “HOLD” symbol switches OFF.
9 Environmental Temperature Test
The calibrator can measure the surrounding environmental temperature, and display it on the top right corner of the LCD.
After switching the calibrator ON, press the (TEMP) key to display the temperature value and the unit of measure at the top
right corner of the LCD. Press again to cancel the measurement.
10 Programming the Calibrator’s Global Settings
Press and hold the (HOLD) key while switching the meter ON. Release the (HOLD) key when “SPFC” is shown on the top
right corner of the LCD. The following parameters can be programmed by the user. The top row of the LCD display shows
the parameter name; the bottom row of the LCD shows the setting. Use the MEAURE (ON) key to scroll the parameters and
then follow the instructions below to configure each parameter.
10.1 Setting Auto-power off time
Step 1: Use the MEASURE (ON) key to display the “AP.OFF” parameter at the top of the LCD (if it’s not already displayed).
Step 2: Set the time from 0-60 minutes using the second pair of 〔S〕/〔T〕keys counting right to left. Each press of the
〔S〕/〔T〕key equals one 10 -minute increment or decrement. Press and hold a key to scroll quickly.
Step 3: To save the setting,press and hold the SOURCE (ON) key until the LCD shows the “SAVE” symbol.
Note: The default value (0) indicates that the automatic power-off function is disabled.
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10.2 Setting Backlight time
Step 1: Use the MEASURE (ON) key to display the “BL.OFF” parameter at the top of the LCD (if it’s not already displayed).
Step 2: Set the time using the 〔S〕/〔T〕keys (the unit of measure for the time is ‘seconds’ and the range is 0-3600
seconds). Each pair of〔S〕/〔T〕keys corresponds to each digit of the LCD reading. Each press of the〔S〕/〔T〕key
increases or decreases the digit. Increasing the digit from 9 or decreasing it from 0 causes the digit to overflow or underflow,
allowing the output value to be set without interruption. Holding down the〔S〕/〔T〕key continuously changes the digit
quickly. The value won’t change if it is increased or decreased to the Maximum or Minimum value.
Step 3: To save the setting,press and hold the SOURCE (ON) key until the LCD shows the “SAVE” symbol.
Notes: When the default value is 0, the backlight will not switch OFF automatically.
10.3 Setting the temperature units
Step 1: Use the MEASURE (ON) key to display the “TEP.U” parameter at the top of the LCD (if it’s not already displayed).
Step 2: Shift between degrees C and F using the right pair of 〔S〕/〔T〕keys.
Step 3: To save the setting,press and hold the SOURCE (ON) key until the LCD shows the “SAVE” symbol.
10.4 Setting frequency
Step 1: Use the MEASURE (ON) key to display the “FrSEt” parameter at the top of the LCD (if it’s not already displayed).
Step 2: Shift between 50Hz and 60Hz using the right pair of 〔S〕/〔T〕keys.
Step 3: To save the setting,press and hold the SOURCE (ON) key until the LCD shows the “SAVE” symbol.
10.5 Setting CMSET
Step 1: Use the MEASURE (ON) key to display the “CMSEt” parameter at the top of the LCD (if it’s not already displayed).
Step 2: For this meter, ensure that “DPM” is selected from the list (PCM, DPM, CAT) using the right pair of arrow keys 〔S
〕/〔T).
Step 3: To save the setting,press and hold the SOURCE (ON) key until the LCD shows the “SAVE” symbol.
10.6 Factory default
Step 1: Use the MEASURE (ON) key to display the “FACry” parameter at the top of the LCD (if it’s not already displayed).
Step 2: Press the SOURCE (ON) key to revert to the default values as shown below:
AP.OFF: 10 minutes
BL.OFF: 10 seconds
TMP.U: Ԩ
FRSET: 50 Hz
CMSET: PCM
Page 26 PRC70-EN-V2.1 12/11
11 Calibration
Please contact Extech Instruments Corporation for instructions on returning the unit for calibration.
12 Replacing the Batteries or Fuses:
Warning
To avoid possible electric shock, remove the test leads from the calibrator before open the battery door and ensure that the
battery door is tightly closed before switching the calibrator ON.
Caution
z To avoid battery leakage and possible explosion ensure correct battery polarity.
z Do not short circuit the battery.
z Do not disassemble, heat, or expose batteries to fire.
z When replacing the batteries, use only the specified type.
z Remove the batteries if the meter is to be stored for a long period.
Step 1: Remove the test leads and charger before replacing the batteries or fuses, and switch OFF the meter.
Figure 16 - Replacing batteries and fuses
Step 2: Remove the protector as shown in Figure 16. With a standard blade screwdriver, turn each battery door screw a
quarter turn counter-clockwise to remove the battery door.
Step 3: Replace with four (4) new AAA alkaline batteries using the instructions shown on the battery door. Replace the
blown fuses with same type F1 (50mA/250V) or F2 (63mA/250V).
Step 4: Reinstall and tighten the battery door, affix the protector before using the meter.
Page 27 PRC70-EN-V2.1 12/11
13 Maintenance
13.1 Cleaning the calibrator
Warning
To avoid electrical shock or damage to the meter, service the meter with specified replacement parts only and do not allow
water to enter the meter housing.
Caution
To avoid damaging the plastic lens and case, do not use solvents or abrasive cleansers.
Clean the Calibrator with a soft cloth dampened with water or water and mild soap.
13.2 Calibration, Repair, and Technical Support Services
Extech offers repar and calibration services for the products we sell. Extech also provides NIST certification for most
products. Call the Customer Care Department for information on calibration services available for this product. Extech
recommends that annual calibrations be performed to verify