Extech Instruments PRC70 User manual
User Guide
Multifunction Process Calibrator
Model PRC70
Page 2 PRC70-EN-V2.1 12/11
1 Introduction
This multifunction process calibrator is a handheld, battery-operated instrument that measures and sources electrical and
physical parameters. (See Table 1)
Table 1 - Source and Measurement Functions
DCI CONT.Measurement
Function
Sourcing
Function
DCV
LOOP OFF LOOP ON
OHM FREQ TC RTD SWITCH
DCV ●●●●●●●●●
RAMP ON × × × × × × × × ×DCI
RAMP OFF ●●●●●●●●●
OHM ●●●●●●●●●
FREQ ●●●●× ●●●●
PULSE ●●●●× ●●●●
SWITCH ●●●●× ●●●●
TC ●●●●●× × ●●
RTD ●●●●●× × ●●
In addition to the functions listed in Table 1, the calibrator includes the following features:
zMeasure and source simultaneously. The upper LCD area displays measurement information and the lower section
displays source information.
zThermocouple measurement/source terminals and built-in lead connector (with RJ compensation)
zManual step source, auto-step, and sweeping-step source
zRoom temperature monitoring for all operations
zMeasurement/source temperature monitoring function
zMeasurement/source mA% display
zMeasurement wave-filter function
zMeasurement manual-hold function
Page 3 PRC70-EN-V2.1 12/11
Supportline(781)8907440
Product specifications subject to change w ithout notice
For the latest version of this User Guide, Software updates, and other
up-to-the-minute product information, visit our website: www.extech.com
Extech Instruments Corporation, 285 Bear Hill Road, Waltham, MA 02451
ISO9001 Certified
2 Warranty and Support Information
Warranty
EXTECH INSTRUMENTS CORPORATION (A FLIR COMPANY) warrants this instrument to be free of defects in parts and
workmanship for one year from date of shipment (a six month limited warranty applies to sensors and cables). If it should become
necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (781)
890-7440 ext. 210 for authorization or visit our website www.extech.com for contact information. A Return Authorization (RA) number
must be issued before any product is returned to Extech. The sender is responsible for shipping charges, freight, insurance and
proper packaging to prevent damage in transit. This warranty does not apply to defects resulting from action of the user such as
misuse, improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification. Extech
specifically disclaims any implied warranties or merchantabil()1.3fitnecess foahe snobe(h li)-6.2(ibl)-6.ean foa( )]TJ1067867 0 TD-0.9.04 Tc0.2106 Twnlly refe,5( )]TJmet, cidoputae, iaasnt612.5(a)1.l(h a( )]T2p)772333 0 T[(b, i)-5.(il()3(ih li)-5.8(mitey to r p)1)19(a)-5.ir fr
Page 4 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.
A Warning identifies conditions and actions that pose hazards to the user; a Caution identifies conditions and actions that
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
INFORMATION
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;
zBefore use, verify the meter’s operation by measuring a known voltage;
zFollow all equipment safety procedures;
zDo 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;
zSelect the proper function and range for the measurement;
zMake sure the battery door is closed and latched before operating the meter;
zRemove test leads from the meter before opening the battery door;
zInspect the test leads for damaged insulation or exposed metal. Check test lead continuity. Replace damaged test leads
before using the meter;
zWhen using the probes, keep fingers behind the finger guards on the probes;
zConnect the common test lead before connecting the live test lead. When disconnecting test leads, disconnect the live
test lead first;
zDo not use the meter if it operates abnormally. Protection may be impaired. When in doubt, have the meter inspected;
zDo 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;
zDo not operate the meter near explosive gas, vapor, or dust;
zUse only four (4) AAA 1.5V batteries, properly installed in the meter case, to power the meter;
zDisconnect the test leads before shifting to different source or measurement functions;
zWhen servicing the meter, use only specified replacement parts.
zTo avoid false readings, which could lead to possible electric shock or personal injury, replace the batteries as soon as
the low battery indicator ( ) appears.
Caution
To avoid possible damage to meter or to equipment under test:
zDisconnect the power and discharge all high-voltage capacitors before testing resistance or continuity.
zUse the proper jacks, functions, and ranges for the measurement or source operation.
Page 5 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
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
Terminal Function
1 Common (COM) return（-）terminal for all
measurement functions
2 Measurement Signals（+）：DCV, OHM, FREQ,
TC, RTD, SWITCH, and CONT (continuity)
3 Measurement Signal（+）：mADC
4
3W Terminal：measurement terminal of the 3W
OHM, RTD
LOOP Terminal：+24VDC Loop Power Terminal
5 Source Signal:（+）DCmA
6 Source Signals：（-）OHM、RTD
7 Common (COM) return（-）terminal for source
functions
8
Source Signal（+）DCV, OHM, TC, RTD, XMT,
FREQ, CYC, and SWITCH
Source Signal:（-）mADC
1
2
4
3
5
Page 6 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 D escriptions
No. Name Function
1~5 Source value set key Increment source set point
6~10 Source value set key Decrement source set point
11 Measurement ON key Switch measurement functions ON or OFF
12 Source ON key Switch source function ON or OFF
13 Power key Switch the power ON or OFF
14 Backlight Switch the backlight ON or OFF
15 Measurement FUNC Key Select measurement function
16 Source FUNC Key Select source function
17 TEMP Key Switch room temperature monitoring function ON or OFF
In TC source or measurement mode, switch the RJ compensation ON/OFF
18 ZERO Key Set the source value to zero-point; In pulse source function, set the pulse number.
19 Measurement RANGE Key Select measurement range; Measurement mA and percentage shifting.
20 Source RANGE Key Select source range; Source mA and percentage shifting.
21 AVG Key Measuring average value
22 25/100% key In mA source function, select 25% or 100% manual step output mode.
In pulse number, frequency or switch source, set the frequency value.
23 HOLD Key Freeze measured value
24 START Key Source auto-pulse number, switch ON mA auto-stepping or sweeping function.
Convert sourced TC temperature and mV, and sourced RTD temperature and Ohms.
25 LOOP Key 24v Loop circuit power: Convert the measured TC temperature and the mV, the
measured RTD temperature and the Ohms.
26
Key
In DCmA source mode, select auto-wave; In frequency/pulse source mode, set
amplitude
Page 7 PRC70-EN-V2.1 12/11
5.3 Display Screen
Figure 4 - LCD display
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
a
b
cd e fgh
jk
l
m
o
p
q
r
s
t
u
v
w
x
y
n
I
Page 8 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.”
zDo not open the instrument’s case. Contact the vendor for service.
zIn 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.
zDo not bring any electrified object close to the input terminals, since this may damage the internal circuitry.
zDo 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.
zIf using an AC Charger, disconnect the power cord plug from the wall outlet when the meter is not in use.
zFor handling precautions regarding the batteries, see “Installing or Replacing the Batteries”.
zNever 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:
Ambient temperature range: 32 to 122oF (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:
zExposed to direct sunlight or close to any heat source.
zExposed to frequent mechanical vibration.
zClose to an electrical noise source, such as high-voltage equipment or motive power sources.
zClose to any source of intensive electric or electromagnetic fields.
zExposed to large amounts of grease fumes, hot steam, dust or corrosive gases.
zExposed 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:
Ambient temperature range: 74oF (23oC) ±5o; ambient humidity range: 20 to 80% RH (non-condensing)
zWhen using the instrument within a temperature range of 32 to 64oF (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 9 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 Batter y 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.
zDo not use a Charger other than the dedicated, supplied Charger.
zDo 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:
zSwitch OFF the calibrator before connecting or disconnecting the Charger from AC power.
zUnplug the Charger from the Charger connection jack of the calibrator when discharging.
zDo 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.
zUse the MEASURE (ON) key to switch the MEASURE mode ON/OFF.
zIf 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%, 1 00% 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 〔〕key to display the auto-stepping mode icon “ ” on the lower part of
the screen; press again to display the auto-sweeping mode icon “ ”. 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:
zPress 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.
zThe 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.
zStarting the mA auto-sweeping mode switches OFF the measurement mode. The mA auto-stepping mode and the
measurement function cannot run simultaneously.
Page 14 PRC70-EN-V2.1 12/11
Page 15 PRC70-EN-V2.1 12/11
Page 16 PRC70-EN-V2.1 12/11
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.
Page 17 PRC70-EN-V2.1 12/11
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 in the lower LCD area.
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.
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 18 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:
zThe frequency range of the pulse can only be changed by pressing (RANGE) in the frequency set mode.
zWhen 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 19 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 “ “ switch symbol.
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:
zThe contact output source function is unavailable if the frequency measurement function is ON.
zThe amplitude and pulse number cannot be set when in the contact output mode.
zThe 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.
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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Table of contents
