Fluke 771 Use and care manual

771
Milliamp Process Clamp Meter
Calibration Manual
November 2007 Rev. 1, 7/19
© 2007-2019 Fluke Corporation. All rights reserved. Product specifications are subject to change without notice.
All product names are trademarks of their respective companies.

LIMITED WARRANTY AND LIMITATION OF LIABILITY
This Fluke product will be free from defects in material and workmanship for 3 years (one year for cable and
clamp) from the date of purchase. This warranty does not cover fuses, disposable batteries or damage from
accident, neglect, misuse or abnormal conditions of operation or handling. Resellers are not authorized to
extend any other warranty on Fluke’s behalf. To obtain service during the warranty period, send your
defective Meter to the nearest Fluke Authorized Service Center with a description of the problem.
THIS WARRANTY IS YOUR ONLY REMEDY. NO OTHER WARRANTIES, SUCH AS FITNESS FOR A
PARTICULAR PURPOSE, ARE EXPRESSED OR IMPLIED. FLUKE IS NOT LIABLE FOR ANY SPECIAL,
INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, ARISING FROM ANY CAUSE
OR THEORY. Since some states or countries do not allow the exclusion or limitation of an implied warranty
or of incidental or consequential damages, this limitation of liability may not apply to you.
Fluke Corporation
P.O. Box 9090
Everett, WA 98206-9090
U.S.A.
Fluke Europe B.V.
P.O. Box 1186
5602 BD Eindhoven
The Netherlands
ООО «Флюк СИАЙЭС»
125167, г. Москва,
Ленинградский проспект дом 37,
корпус 9, подъезд 4, 1 этаж
11/99

i
Table of Contents
Title Page
Introduction ........................................................................................................ 1
Contacting Fluke ................................................................................................ 2
Safety Information .............................................................................................. 2
Symbols ............................................................................................................. 3
Specifications ..................................................................................................... 4
Getting Acquainted with the Meter ..................................................................... 5
Maintenance ....................................................................................................... 7
Cleaning the Meter ........................................................................................ 7
Battery Replacement ..................................................................................... 7
Performance Tests ............................................................................................. 9
Required Equipment ...................................................................................... 9
Testing the Batteries ...................................................................................... 9
Testing the Display ........................................................................................ 10
Display Hold Test ........................................................................................... 10
Backlight Test ................................................................................................ 10
Spotlight LED Test ......................................................................................... 10
Zero Test ....................................................................................................... 10
Accuracy Tests .............................................................................................. 11
Calibration Adjustment ....................................................................................... 12
Adjustment Subroutines ................................................................................. 12
Front Panel Operation for Adjustment ........................................................... 12
Calibration Error Messages ........................................................................... 13
Calibration Adjustment Procedure ................................................................. 13
Temperature Adjustment Procedure ............................................................. 14
Low Range Adjustment Procedure ................................................................ 14
High Range Adjustment Procedure ............................................................... 14
Phase Adjustment Procedure ........................................................................ 15
User Replaceable Parts ..................................................................................... 16

771
Calibration Manual
ii

1
771
Milliamp Process Clamp Meter
Introduction
XW Warning
To prevent electric shock or personal injury, do not perform the
calibration verification tests or calibration procedures
described in this manual unless you are qualified to do so.
The information provided in this manual is for the use of
qualified personnel only.
This manual provides the complete verification and adjustment procedure for the
771 Milliamp Process Clamp Meter (the Meter or Product).
The Meter allows closed-case calibration using reference sources. It measures
the reference signals, calculates the correction factors, and stores them in
memory. The instrument should be calibrated after repair, or if it fails a
performance test.
The 771 Calibration Manual provides the following information:
• Precautions and safety information
• Specifications
• Basic maintenance
• Calibration verification procedure
• Replaceable parts and accessories
For complete operating instructions, refer to the 771 Instruction Sheet.

771
Calibration Manual
2
Contacting Fluke
To contact Fluke, call one of the following telephone numbers:
• Technical Support USA: 1-800-44-FLUKE (1-800-443-5853)
• Calibration/Repair USA: 1-888-99-FLUKE (1-888-993-5853)
• Canada: 1-800-36-FLUKE (1-800-363-5853)
• Europe: [phone]
• Japan: [phone]
• Singapore: [phone]
• China: [phone]
• Brazil: [phone]
• Anywhere in the world: [phone]
Or, visit Fluke's website at www.fluke.com.
To register your product, visit http://register.fluke.com.
To view, print, or download the latest manual supplement, visit
http://us.fluke.com/usen/support/manuals.
Safety Information
A Warning identifies conditions and procedures that are dangerous to the user.
A Caution identifies conditions and procedures that can cause damage to the
Product or the equipment under test.
XWWarning
To prevent possible electrical shock, fire, or personal injury:
• Carefully read all instructions.
• Do not alter the Product and use only as specified, or the
protection supplied by the Product can be compromised.
• Before each use, inspect the Meter and cable for damage.
Look for cracks and missing portions of the clamp and
cable. Do not use if clamp is damaged.
• Do not use to measure ac current.
• Do not touch voltages >30 V ac rms, 42 V ac peak, or 60 V dc.
• Do not work alone.
• Use the Clamp only on insulated conductors. Use caution
around bare conductors or bus bars. To prevent electrical
shock, do not touch the conductor.
• Replace the batteries when the low battery indicator shows
to prevent incorrect measurements.

Milliamp Process Clamp Meter
Symbols
3
• Comply with local and national safety codes. Use personal
protective equipment (approved rubber gloves, face
protection, and flame-resistant clothes) to prevent shock and
arc blast injury where hazardous live conductors are
exposed.
• Hold the Product behind the tactile barrier. See Figure 1.
• Do not use on non-insulated conductors.
WCaution
To prevent damage to the Meter, do not open the Meter for
cleaning. Do not use solvents to clean it, and do not immerse it
in liquid.
Symbols
Table 1 explains the symbols that are used on the Meter or in this manual.
Table 1. Symbols
- Do not apply around, or remove from HAZARDOUS LIVE conductors
 Consult user documentation.
W WARNING. RISK OF DANGER.
X WARNING. HAZARDOUS VOLTAGE. Risk of electric shock.
 On/Off
 Battery
 DC (Direct Current)
P Conforms to European Union directives.
 Conforms to relevant Australian Safety and EMC standards
) Certified by CSA Group to North American safety standards.
~
This product complies with the WEEE Directive marking requirements. The affixed
label indicates that you must not discard this electrical/electronic product in domestic
household waste. Product Category: With reference to the equipment types in the
WEEE Directive Annex I, this product is classed as category 9 "Monitoring and
Control Instrumentation" product. Do not dispose of this product as unsorted municipal
waste.

771
Calibration Manual
4
Specifications
Current Ranges ±20.99 mA ±21.0 mA to ±99.9 mA
Resolution 0.01 mA 0.1 mA
Accuracy
20.99 mA range
99.9 mA range
0.2 % reading ±5 digits
1 % reading ±5 digits
Maximum Reading ±99.9 mA
Influence of Earth’s Field <0.20 mA
Battery 2 AA 1.5 V Alkaline, IEC LR6
Battery Life 40 hours
Size (H X W X L) 59 mm x 38 mm x 212 mm (2.32 in x 1.49 in x 8.34 in)
(with clamp nested)
Weight 260 g (9.17 oz) (Including battery)
Operating Temperature -10 °C to 50 °C (14 °F to 122 °F)
Storage Temperature -25 °C to 60 °C (-13 °F to 140 °F)
Operating Humidity <90 % @ <30 °C (86 °F)
<75 % @ 30 °C to 50 °C (86 °F to 122 °F)
Operating Altitude 0 m to 2000 m
Storage Altitude None
IP Rating IP40
Vibration Requirements Random 2 g, 5 Hz to 500 Hz
Temperature Coefficients 0.1x (specified accuracy)/°C (<18 °C or >28 °C)
AC Noise Rejection ≥5 Hz, the Meter reading is the mean value of the measured current
Diameter of Measurable
Conductor
4.5 mm maximum
Electrical Compatibility (EMC)
General IEC 61010-1: Pollution Degree 2
International
IEC 61326-1: Portable Electromagnetic Environment;
IEC 61326-2-2
CISPR 11: Group 1, Class A
Group 1: Equipment has intentionally generated and/or uses conductively-coupled radio frequency
energy that is necessary for the internal function of the equipment itself.
Class A: Equipment is suitable for use in all establishments other than domestic and those directly
connected to a low voltage power supply network that supplies buildings used for domestic purposes.
There may be potential difficulties in ensuring electromagnetic compatibility in other environments due to
conducted and radiated disturbances.
Caution: This equipment is not intended for use in residential environments and may not provide
adequate protection to radio reception in such environments.

Milliamp Process Clamp Meter
Getting Acquainted with the Meter
5
Getting Acquainted with the Meter
Figure 1 shows the Meter functions and features.
1
2
3
4
5
6
e
g
e01a.emf
Number Description
 Turn on and turn off the Meter. When the Meter is in sleep mode, press this button to wake it up.
 Captures and holds the current reading
 Removes interference and zeros the display
 Measurement spotlight LED button
 Measurement spotlight LED
 Detachable clamp
 Turn on and turn off the backlight
 LCD
 Tactile Barrier docked and un-docked
Figure 1. The 771 Milliamp Process Clamp Meter

771
Calibration Manual
6
h Static Awareness h
X Semiconductors and integrated circuits can be damaged by electrostatic
discharge during handling. This notice explains how to minimize damage to
these components.
1. Understand the problem.
2. Learn the guidelines for proper handling.
3. Use the proper procedures, packaging, and bench techniques.
Follow these practices to minimize damage to static sensitive parts.
XW Warning
To prevent electric shock or personal injury. De-
energize the product and all active circuits before
opening a product enclosure, touching or handling
any PCBs or components.
• Minimize handling.
• Handle static-sensitive
parts by non-conductive
edges.
• Do not slide static-
sensitive components
over any surface.
• When removing plug-in
assemblies, handle only
by non-conductive
edges.
• Never touch open-edge
connectors except at a
static-free work station.
• Keep parts in the original
containers until ready for
use.
• Use static shielding
containers for handling
and transport.
• Avoid plastic, vinyl, and
Styrofoam® in the work
area.
• Handle static-sensitive
parts only at a static-
free work station.
• Put shorting strips on
the edge of the
connector to help
protect installed static-
sensitive parts.
• Use anti-static type
solder extraction tools
only.
• Use grounded-tip
soldering irons only.

Milliamp Process Clamp Meter
Maintenance
7
Maintenance
XWWarning
To prevent possible electric shock or personal injury, repairs or
servicing not covered in this manual should be performed only
by qualified personnel.
Cleaning the Meter
XWWarning
To prevent electrical shock, remove any input signals before
cleaning.
WCaution
To prevent damaging the Meter, do not use aromatic
hydrocarbons or chlorinated solvents for cleaning. These
solutions will react with the plastics used in the Meter.
Clean the instrument case with a damp cloth and mild detergent.
Note
Dirt or debris on the surface of the sensor in the clamp jaw will
impact the precision of measurements. For best performance, clean
the sensor surfaces with a soft cloth and a solution of Isopropyl
alcohol as needed.
Battery Replacement
XWWarning
To prevent possible electrical shock, fire, or personal injury:
• Replace the batteries when the low battery indicator shows
to prevent incorrect measurements.
• Remove the batteries if the Product is not used for an
extended period of time, or if stored in temperatures >50 °C.
If the batteries are not removed, battery leakage may result.
To replace the batteries, see Figure 2:
1. Turn off the Meter.
2. Use a flat head screwdriver to loosen the battery access door fastener and
remove the door from the case bottom.
3. Remove the batteries.
4. Replace the batteries with two new AA batteries.
5. Reattach the battery access door to the case bottom and tighten the fastener.

771
Calibration Manual
8
ege02.emf
Figure 2. Changing the Batteries

Milliamp Process Clamp Meter
Performance Tests
9
Performance Tests
XWWarning
To prevent electrical shock, personal injury, or fire:
• Do not perform the verification tests or calibration
adjustment described in this manual unless you are
qualified to do so.
• Repairs or servicing should be performed only by qualified
personnel.
The following tests are used to verify the functions of the Meter. If the Meter fails
any of the verification tests, repair is necessary. For service, see Contacting
Fluke.
Required Equipment
Required equipment for the performance tests is listed in Table 2. If the
recommended models are not available, equipment with equivalent specifications
may be used.
Table 2. Required Equipment
Equipment Minimum Required
Characteristics Recommended Model
Calibrator
DC Current Accuracy:
Range:
20.99 mA = 0.11 %
99.9 mA = 0.375 %
5520A or equivalent
1 loop insulated copper wire Insulated 18 gauge, minimum, copper
wire, 6-inch diameter
Testing the Batteries
Prior to performing the following tests, check the batteries with a multimeter and
replace as necessary. See Battery Replacement.

771
Calibration Manual
10
Testing the Display
1. Press and hold  while powering on the Meter.
2. Compare the Meter display to Figure 3.
3. Check all display segments for clarity and contrast.
fdp1.emf
Figure 3. Display Test
Display Hold Test
1. Power on the Meter and allow time for the normal operating display to
appear.
2. Press  and observe that  appears on the display.  flashes at
3 to 4 second intervals.
Backlight Test
1. Power on the Meter and allow time for the normal operating display to come
up.
2. Press  and observe that the backlight comes on.
Spotlight LED Test
1. Power on the Meter and allow time for the normal operating display to come
up.
2. Press  and observe that the spotlight LED comes on.
Zero Test
1. Power on the Meter and allow time for the normal operating display to come
up.
2. Press . The main display momentarily reads 0.00, and the percentage
scale momentarily reads -25.0%.

Milliamp Process Clamp Meter
Performance Tests
11
Accuracy Tests
Accuracy specifications are valid for 1 year after calibration when measured at an
operation temperature of 18 °C to 28 °C. Allow the Meter to stabilize at room
temperature prior to performing the accuracy tests.
Table 3 lists the required performance test points for verifying Meter accuracy. A
zero adjustment must be performed prior to completing each performance test
point.
Perform the tests as follows:
1. Connect a single loop of 14 gauge insulated copper wire to the calibrator
AUX output terminals.
2. Clamp the Meter jaw around the wire with the jaw arrow pointing toward the
calibrator LO terminal.
3. Output 0 mA dc from the calibrator.
4. Press  on the Meter.
5. Set the calibrator output for the value in Step 1 of Table 3.
6. Compare the Meter displayed reading with the display reading limits in
Table 3.
7. Complete steps 2-4 for each calibrator output setting in Table 3.
8. If the Meter fails to meet any of the Display Reading Limits, it requires
calibration adjustment, or repair. See Calibration Adjustment or Contacting
Fluke.
Table 3. Accuracy Tests
Step Unit Under Test
Function
Calibrator
Output Setting
Unit Under Test
Display Reading Limits
Lower Limit Upper Limit
1. mA dc 100 mA dc 98.5 101.5
2. -100 mA dc -101.5 -98.5
3. 20 mA dc 19.91 20.09
4. -20 mA dc -20.09 -19.91
5. 12 mA dc 11.93 12.07
6. -12 mA dc -12.07 -11.93
7. 4 mA dc 3.94 4.06
8. -4 mA dc -4.06 -3.94

771
Calibration Manual
12
Calibration Adjustment
Adjustment Subroutines
The Meter features closed-case calibration adjustment using a known reference
source. The Meter measures the applied reference source, calculates correction
factors, and stores the correction factors in nonvolatile memory.
There are four adjustment subroutines in the Meter adjustment procedure:
• Low Range (±20 mA)
• High range (±100 mA)
• Temperature
• Phase
Note
Temperature adjustment should always be performed prior to
performing the other adjustment routines. The phase adjustment
routine is ONLY required if the unit is repaired or the current clamp is
replaced.
Front Panel Operation for Adjustment
Use a small probe to press the calibration button once to enter the Meter’s
calibration mode. The calibration button is usually covered by the factory
calibration seal. A second press of the button saves new calibration constants
and exits calibration mode. See Figure 4.
In calibration mode,  is used to select subroutines: low range, high range,
temperature, or phase. A short press of  (<1 second) will toggle between low
and high range subroutines. A long press (>1 second) will toggle between
temperature and phase subroutines.
• Pressing  is valid for all subroutines and normal operation. Pressing 
will zero the reading.
• In the low and high range subroutines,  and  are used to adjust the
negative and positive gain of the range.
• In the temperature subroutine, only  is valid for adjustment.
• In the phase subroutine,  and  are used to adjust the phase of two
sensor-excitation signals by increasing or decreasing a parameter.

Milliamp Process Clamp Meter
Calibration Adjustment
13
Calibration Button
fdp3.emf
Figure 4. Accessing the Calibration Button
Calibration Error Messages
Table 4 lists the calibration error messages that can be shown on the Meter
display. The suggested actions to eliminate messages are also listed.
Table 4. Error Messages
Error
Message Cause of Error Suggested Action
CAL ERR1
The difference between the input level and the zero
point is less than the minimal threshold when
performing low range and high range adjustments.
Check current loop and ensure
correct current is generated.
CAL ERR2 Calibration parameter checksum failure.
Execute all adjustments
including temperature and
phase.
CAL ERR3 Code checksum failure. The Meter requires repair.
Calibration Adjustment Procedure
Allow the Meter to stabilize to room temperature before beginning the calibration
adjustment.
To prepare for adjustment:
1. Remove the battery door and calibration seal.
2. Clamp the current loop in the current flow direction where required.
3. Turn the meter on and wait at least 10 seconds for warming up.
4. Press the hidden calibration button with a probe to enter calibration mode.
See Figure 4. Note
If the Jaw Assembly has been replaced, do the Phase Adjustment
Procedure before you continue.

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Calibration Manual
14
Temperature Adjustment Procedure
The percentage display should show t23, if not:
1. Press  for >1 second until t23 appears.
2. Wait at least 60 seconds for the internal temperature to balance.
3. Press  to adjust the temperature.
Low Range Adjustment Procedure
1. Clamp the Meter’s current clamp around an insulated 18-gauge copper wire
with 6-inch diameter. Current flow should be in the direction of the arrow on
the current clamp.
2. Press  <1 second until CAL 20 appears on percentage display.
3. Output 0 µA dc from the calibrator.
4. Wait at least 15 seconds for the Meter’s internal circuits to stabilize.
5. Press  on the Meter to zero the reading.
6. Output 20 mA dc from the calibrator.
7. Wait at least 15 seconds for the Meter’s internal circuits to stabilize.
8. Press  on the Meter to adjust the positive gain.
9. Output -20 mA dc from the calibrator.
10. Wait at least 15 seconds for the Meter’s internal circuits to stabilize.
11. Press  on the Meter to adjust the negative gain.
High Range Adjustment Procedure
1. Clamp the Meter’s current clamp around an insulated 18-gauge, copper wire,
with 6-inch diameter. Current flow should be in the direction of the arrow on
the current clamp.
2. Press  <1 second until CAL 100 appears on percentage display.
3. Output 0 µA dc from the calibrator.
4. Wait at least 15 seconds for the Meter’s internal circuits to stabilize.
5. Press  on the Meter to zero the reading.
6. Output 100 mA dc from the calibrator.
7. Wait at least 15 seconds for the Meter’s internal circuits to stabilize.
8. Press  on the Meter to adjust the positive gain.
9. Output -100 mA dc from the calibrator.
10. Wait at least 15 seconds for the Meter’s internal circuits to stabilize.
11. Press  on the Meter to adjust the negative gain.
12. If the Meter’s current clamp has NOT been replaced, press the calibration
button to exit the calibration mode.
Note
The following procedure is not required unless the Meter’s current
clamp has been replaced.

Milliamp Process Clamp Meter
Calibration Adjustment
15
Phase Adjustment Procedure
1. Clamp the Meter’s current clamp around an insulated 18-gauge, copper wire,
with 6-inch diameter. Current flow should be in the direction of the arrow on
the current clamp.
2. Press  >1 second until the percentage display indicates the Meter’s
currently saved 3-digit phase value.
3. Output 0 µA dc from the calibrator.
4. Press  on the Meter to zero the reading.
5. Rotate the Meter’s clamp around the current loop conductor and record the
minimum and maximum values of the Meter’s display reading. See Figure 5.
6. Use  and , to adjust the difference between the minimum and
maximum value recorded in Step 5, until the reading difference is less than
0.05 mA.
7. Press the hidden calibration button to exit calibration mode. See Figure 4.
Rotate Meter clamp around
current loop conductor
fdp5.emf
Figure 5. Phase Adjustment

771
Calibration Manual
16
User Replaceable Parts
Table 5 and Figure 6 list all user replaceable parts.
Table 5. Replaceable Parts
Item ID Description P/N Qty
 Decal 2723063 1
 Case top assembly
(does not include decal, order separately) 2720362 1
 Keypad 2723056 1
 Jaw assembly (Includes cable) [1] 2722971 1
 Screw, m2.2 x 0.8, 8mm, pan, phillips, steel, zinc-black chromate,
thread form 1991287 2
 Case, bottom
(does not include battery contact, order separately) 2720285 1
 Cable cleat 2720328 1
 Screw, 4-14, 0.375, pan, phillips, steel, zinc-black chromate, thread
form 2800097 2
 Battery contact, dual 666435 1
 Screw, m3, 13.5 mm, pan, phillips, steel, zinc-black chromate,
thread form 2388412 2
 Battery, primary, mno2-zn, 1.5 v, 2.24 ah, 15 a, lr6, alkaline, aa,
14 x 50 mm, bulk 376756 2
 Battery pad, urethane, adhesive-back, 20.0 mm l, 20.0 mm w,
5.0 mm thk 2687457 1
 Battery door
(does not include fastener, order separately) 2720304 1
 Access door fastener 948609 1
 LED housing 2720319 1
- Soft case, black/yellow 2726174 1
- 771 Instruction Sheet 2567301 1
[1] If the Jaw Assembly has been replaced, complete the Calibration Adjustment Procedure and Phase Adjustment Procedure.