Chauvin Arnoux®, Inc. d.b.a. AEMC® Instruments certifies
that this instrument has been calibrated using standards
and instruments traceable to international standards.
We guarantee that at the time of shipping your instrument
has met its published specifications.
An N.I.S.T. traceable certificate may be requested at the
time of purchase, or obtained by returning the
instrument to our repair and calibration facility, for a
nominal charge.
The recommended calibration interval for this instrument
is 12 months and begins on the date of receipt by the
customer. For recalibration, please use our calibration
services. Refer to our repair and calibration section at
Thank you for purchasing the Current Probe MR525 or MR526. For best results
accordance with standard ISO 14040.
from your instrument and for your safety, read the following operating instructions
carefully and comply with the precautions for use.
This instrument is compliant with the IEC 61010-2-032 safety standard for voltages
of 300V with respect to earth in measurement category IV, or 600V in category III.
Symbols
WARNING, risk of DANGER! The operator must refer to these instructions
whenever this danger symbol appears.
Application or withdrawal authorized on conductors carrying dangerous
voltages. Type A current sensor as per IEC 61010-2-032.
Equipment is protected by double insulation.
Battery.
USB.
Useful information or tip.
Direction of the current.
The product is declared recyclable following an analysis of the life cycle in
The CE marking guarantees conformity with European directives and with
regulations covering EMC.
The trash can with a line through it means that in the European Union, the
product must undergo selective disposal for the recycling of electric and
electronic material, in compliance with Directive WEEE 2002/96/EC.
Definition of Measurement Categories (CAT)
CAT IV Corresponds to measurements taken at the source of low-voltage
installations.
Example: power feeders, counters and protection devices.
CAT III Corresponds to measurements on building installations.
Example: distribution panel, circuit-breakers, machines or fixed industrial devices.
CAT II Corresponds to measurements taken on circuits directly connected to lowvoltage installations.
Example: power supply to domestic electrical appliances and portable tools.
These instructions are intended to ensure the safety of users and proper operation
of the instrument. Failure to observe these safety instructions may result in electric
shock, fire, explosion, and destruction of the instrument and/or installations.
The operator and/or the responsible authority must carefully read and clearly
understand the various precautions to be taken in use.
Do not use the instrument on networks on which the voltage or category
exceeds instrument specifications.
Never exceed the protection limits stated in the specifications.
Observe the environmental conditions of use, including relative humidity,
altitude, degree of pollution, and place of use.
Do not use the instrument if it appears to be damaged, incomplete, or not
properly closed.
Before each use, check the condition of the insulation on the leads, housing,
and accessories. Any component on which the insulation is deteriorated (even
partially) must be set aside for repair or scrapping.
When handling the instrument, keep your fingers behind the physical guards.
Use suitable means of protection.
All troubleshooting and metrological checks must be performed by competent
Upon receiving your shipment, make sure that the contents are consistent with the
packing list. Notify your distributor of any missing items. If the equipment appears
to be damaged, file a claim immediately with the carrier and notify your distributor
at once, giving a detailed description of any damage. Save the damaged packing
container to substantiate your claim.
Ordering Information
AC/DC Current Probe Model MR525 ........................................... Cat. #1200.81
Includes 9V battery, multi-language safety data sheet and user manual
AC/DC Current Probe Model MR526 ........................................... Cat. #1200.83
Includes 9V battery, multi-language safety data sheet and user manual
Replacement Parts/Accessories:
Cable – 6’ USB type A to Micro type B ............................................. Cat. #2138.66
Adapter – US Wall plug to USB ........................................................ Cat. #2153.78
The Models MR525 and MR526 are clamp-on current probes that measure DC
currents up to 1400A, AC currents up to 1000A
AC+DC currents without opening the circuit in which the currents flow. They
indicate the shape and amplitude of the current measured in the form of a voltage.
These instruments can be used with a multimeter, wattmeter, recorder, and other
instruments. They can be powered by a battery or with 5V
micro‑USB cable.
The MR525 and MR526 include the following features:
range overage indicator
power supply indicator
zero adjustment
Auto Standby feature
one or two ranges, depending on the model (sensitivity 1 and 10mV/A)
micro‑USB connector to connect an external power supply
Before changing batteries: set the switch to OFF and remove the clamp
2.1 Battery Installation
from the circuit under measurement.
1. Using a screwdriver, remove the battery compartment cover (1) from the
back of the housing (see Figure 2).
2. Connect the battery to the snap-on connector (2), observing polarity.
3. Place the battery into the battery compartment (3).
4. Replace the battery compartment cover and screw it onto the housing.
Figure 2
2.2 External Power (Optional)
For long‑term measurements, you can connect the clamp to external power via any
micro‑USB adapter that delivers 100mA or more. If external power is disconnected,
the clamp automatically switches to battery operation.
The isolation between the type B micro‑USB connector and the measurement
output is 600V CAT III. This enables you to safely connect the clamp to measuring
instruments with uninsulated inputs. The type B micro‑USB connector must not be
in contact with conductors or uninsulated parts at dangerous voltage.
When operating on external power, the Auto Standby feature is disabled. The color
of the ON indicator shows whether automatic standby is enabled (green) or
disabled (yellow).
Turn on the clamp by pushing the slide switch to the 1mV/A or 10mV/A setting:
1mV/A corresponds to the 1400A range (MR525 and MR526)
10mV/A corresponds to the 150A range (MR526)
The green ON indicator should light up:
If indicator blinks, less than 4 hours of battery life remains
If indicator fails to light, replace the battery (see § 4.2)
2.4 Auto Standby
After 10 minutes of operation without user action (such as pressing the DC Zero
button), the clamp automatically enters Standby mode. In this mode, the ON
indicator goes OFF.
To reactivate the clamp, press DC Zero button or change the switch to any setting
other than OFF.
To disable automatic Standby, press and hold down DC Zero when turning the
instrument ON. The ON indicator blinks to indicate that the request has been
applied; and then glows steady yellow when you release the DCZero button.
2.5 DC Zero Adjustment
1. Remove the clamp from the circuit under measurement.
2. Turn the clamp ON.
3. Connect the clamp to the measuring instrument. The phase is on the red
lead.
4. Press the DC Zero button.
5. The OL indicator lights for approximately three seconds to indicate that
the zero adjustment is in progress.
6. If the zero has been correctly adjusted, the OL indicator goes OFF.
If it remains ON, the zero cannot be adjusted. In this case, ensure the
clamp is not on a conductor and that its jaws are correctly closed. Then
press DC Zero again.
Alternately, turn the clamp OFF and then back ON. The previous zero
adjustment will remain in effect.
2. Clamp the jaws around the conductor to be measured. Use the centering
marks on the jaws to position the clamp around the conductor. If the
measurement is to be used in a power calculation, ensure the arrow on
the clamp jaws (see Figure 1) points in the direction of the current flow:
source
3. Release the trigger, ensuring the jaws are completely and correctly
closed.
4. Observe the measurement displayed on the measuring instrument.
5. If the OL indicator lights, the current is too high to be measured. If you are
using the MR526 and the sliding switch is set to the 10mV/A range,
change the setting to 1mV/A.
load.
Figure 3 (MR526 shown)
2.6.2 Converting to Current
The MR525 and MR526 can both measure current up to 1400A, with 1mV of output
corresponding to 1A. In addition, the MR526 provides a second measurement
range up to 150A, with 10mV corresponding to 1A.
To convert the clamp output to current, divide the voltage reading on the connected
measuring by the V/A coefficient. For example, in the 1400A range a reading of
100mV corresponds to a current of 100A.
Position of the conductor Centered on the marks on the jaws
Measurement frequency DC to 65Hz sine wave
External electrical field zero
External DC magnetic field (earth) <40A/m
External AC magnetic field zero
Input impedance ≥ 1MΩ and ≤100pF
The intrinsic uncertainty is the error defined under the reference conditions. It is
expressed as a percentage of the output signal (R) plus an offset in mV:
±(a% R + b)
Dimensions (L x W x H): 9.3” x 3.8” x 1.7” (224 x 97 x 44mm)
Weight: approximately 18.3oz (520g)
Cable: 4.9’ (1.50m)
Clamping diameter:
1.5” (39mm) in diameter, two cables 1” (25.4mm) in diameter, one 1.97 x 0.49”
(50 x 12.5mm) bar
or two 0.98 x 0.2” (25 x 5mm) bars or 1.24 x 0.30” (31.5 x 10mm), three 0.98 x
0.31” (25 x 8mm) bars, two 0.98 x 0.2” (25 x 5mm) bars
Figure 4
3.7.1 Housing Protection
Protection index:
IP 40 per IEC 60529
IK 06 per IEC 62262
Drop test per IEC 61010-2-032.
3.8 International Standards
The instrument is compliant with IEC 61010-2-032, 300 V in CAT IV or 600 V in
CAT III.
Double or reinforced insulation
Type of current sensor per IEC 61010-2-032: type A
3.9 Electromagnetic Compatibility
The device is in conformity with standard IEC 61326-1.
Except for the battery, the instrument contains no parts that can be
replaced by personnel who have not been specially trained and
accredited. Any unauthorized repair or replacement of a part by an
"equivalent" may gravely impair safety.
4.1 Cleaning
Disconnect the instrument completely.
Use a soft cloth, dampened with soapy water.
Rinse with a damp cloth and dry rapidly with a dry cloth or forced air.
Do not use alcohol, solvents, or hydrocarbons.
Keep the clamp jaws as clean as possible.
4.2 Battery Replacement
The battery must be replaced if the ON indicator remains unlit when the instrument
is turned ON.
1. Disconnect the instrument completely and set the switch to OFF.
2. Remove the battery compartment cover from the instrument casing (see § 2.1).
3. Remove the old battery.
4. Insert the replacement battery into the snap-in battery connector, and place it
into the battery compartment.
5. Replace the battery compartment cover.
Spent batteries must not be treated as ordinary household waste. Take
them to the appropriate collection point for recycling.