Microtest 7110 User manual

7110 / 7120
Single-Phase Power Meter
User Manual
Version: 1.01
Issued Date: Sep 2015

1
+ Safety Instructions
Pay careful attention to all safety instructions below when operating or
maintaining the device. Disregarding these instructions and other warnings
detailed in this manual constitutes a severe violation of the design,
manufacture and operating safety standards of this device.
+Maintenance Instructions
Operators must not remove the protective covers from the instruments. A
qualified maintenance technician must perform all internal parts replacements
or internal calibrations. Never replace any part while the power cord is plugged
in. In special circumstances, dangerous voltages may still be present within the
device after the power supply cord had been disconnected. Disconnect the
power supply and take any necessary measures to discharge electricity before
touching internal components to prevent injury.
+ Earthing the Instrument(s)
Earth all instrument power sources to minimize risks of electrical shock.
+ Never Perform Maintenance or Internal Calibration Work
Alone
Never perform internal device maintenance or internal calibration work by
yourself.
+Never Replace Parts Yourself or Modify Device Functions or
Structure
Never install surrogate parts onto the machine or undertake any device
modifications yourself without the express permission of Microtest, as you may
increase the levels of danger associated with the device or damage the device.
Please return any malfunctioning instruments to Microtest for professional
repairs guaranteeing the device's continued safety.
+ Product Warranty
Microtest provides a quality guarantee for this product for one year from the
dispatch date of the product; however, warranty life may be different for special
parts or different product specifications. Microtest will take responsibility for all
maintenance and replacement of products found to have an actual defect
during the life of the warranty (Microtest will determine the nature of the defect).
Microtest guarantees that all software and hardware designated for use with

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instruments can be used immediately upon installation. Microtest does not
guarantee that instrument software and/or hardware will not disconnect or
produce errors during operation.
+ Product Warranty Scope
The above guarantees and warranty do not apply if a customer has failed to
use the product correctly, has modified or repaired the device or replaced parts
without permission from Microtest, has misused the product, or has installed or
repaired the product in an environment that does not meet the specified
conditions.
Microtest Corporation reserves all rights.
Declaration: Microtest Corporation reserves the rights to modify this
manual without notification of any changes or modifications.

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Chapter 1 Cautions ....................................................................................5
Section 1.1 Safety Labels...............................................................................5
Section 1.2 Never modify the device or perform internal calibrations
yourself. ........................................................................................5
Section 1.3 Static Electricity............................................................................5
Section 1.4 Earthing.........................................................................................6
Section 1.5 Power Supply...............................................................................6
Section 1.6 Warming-Up.................................................................................6
Section 1.7 Device Malfunctions....................................................................6
Section 1.8 After Testing.................................................................................6
Section 1.9 Installation and Storage..............................................................7
Section 1.10 Emergency Measures.................................................................7
Chapter 2 Foreword ...................................................................................8
Section 2.1 Features........................................................................................8
Section 2.2 Measuring Functions ..................................................................9
Section 2.3 Function Flow-Chart....................................................................9
Chapter 3 Wiring.......................................................................................10
Section 3.1 Connecting to the Power Supply and Testing Items............10
Section 3.2 F71201-Exclusive Jig Internal Measuring Wiring
Schematic Diagram...................................................................11
Chapter 4 Operating Settings..................................................................12
Section 4.1 Measurement Mode..................................................................12
Section 4.2 Measurement range..................................................................13
Section 4.3 Averaging....................................................................................14
Section 4.4 Update Rate...............................................................................15
Section 4.5 Synchronization.........................................................................16
Section 4.6 Harmonic Operation Mode Selection.....................................21
Section 4.7 Start Line and Frequency Filter Function ..............................22
Section 4.8 Set Frequency CF Value..........................................................24
Section 4.9 Setting 4th Display Measurement Values..............................25
Section 4.10 Keyboard Lock...........................................................................26
Section 4.11 Store/Load Panel Settings Configuration ..............................27
Section 4.12 Set GPIB Address.....................................................................28
Section 4.13 Remote Control Mode ..............................................................29
Section 4.14 Set RS232 Baud rate and Final Character............................30
Section 4.15 The SCALE Function................................................................31
Section 4.16 Use Power Integrator................................................................33

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Section 4.17 Power Supply Frequency Parameters...................................34
Section 4.18 Calibrate to Zero........................................................................35
Section 4.19 Software Version Look-up........................................................36
Section 4.20 Real time measure data storing..............................................37
Section 4.21 Reso Settings.............................................................................39
Section 4.22 Gauge Head Power Consumption Deductions.....................41
Chapter 5 Display Measurement Values.................................................42
Section 5.1 Panel Description......................................................................42
Section 5.2 Measurement Items:.................................................................46
Section 5.3 Display A Measurement Display Area....................................47
Section 5.4 Display B Measurement Display Area....................................48
Section 5.5 Display C Measurement Display Area ...................................49
Chapter 6 Electrical Features Specifications.........................................50
Chapter 7 GPIB Instruction Sets.............................................................64
Section 7.1 Serial Communications Specifications...................................64
Section 7.2 Symbols......................................................................................64
Section 7.3 Commands.................................................................................64
Appendix…………….....................................................................................85
Version……...................................................................................................85

5
Chapter 1 Cautions
Do not use this instrument outside and avoid humid or dusty areas. Use of this
instrument in an improper setting can increase the risk of electrical shock.
Carefully read all safety instructions before using the device to prevent
accidents due to misuse.
Section 1.1 Safety Labels
The following safety labels may appear in this user manual and
on the device itself.
Caution: Carefully read the user manual for detailed information.
Earthing Required: Check that this terminal is earthed before
operating the device to prevent electrical shocks due to leakage or
contact with the housing.
: Improper use of the device may result in instrument or testing
object malfunctions.
: Improper use of the device may result in injury or death.
Section 1.2 Never modify the device or perform
internal calibrations yourself.
Never install surrogate parts onto the machine or undertake any device
modifications and internal calibrations yourself without the express
permission of Microtest, as you may increase the levels of danger
associated with the device or damage the device.
Section 1.3 Static Electricity
Keep items bearing static electricity away from the device to prevent
damage.

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Section 1.4 Earthing
A safe earthing terminal is located on the outer housing of the back panel
of the device; check that this terminal is properly earthed to prevent
contact with the housing and risk of electrical shock.
Section 1.5 Power Supply
You must use a power supply cable that meets local national
specifications and an IEC320-compatible connector to connect the cable
to the instrument. The user must check that the earth wire is properly
earthed. If a fuse is included in the power supply plug it must be a 3.15A
fuse compatible with relevant safety regulations. Always check before
use to ensure A/C power supply and voltage values are between
100V-240V @ 50/60Hz.
Section 1.6 Warming-Up
The testing device can be used normally immediately after switching the
power on, but will not meet accuracy specifications unless allowed to
warm up for 30 minutes.
Section 1.7 Device Malfunctions
Return all malfunctioning instruments to the manufacturer for
professional repair in order to ensure the accuracy and operational safety
of the instrument.
Section 1.8 After Testing
Please turn the device off at the power source if it will not be used for a
long period of time.

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Section 1.9 Installation and Storage
The device may be operated normally in temperatures of 18-28°C with up
to 80% RH. The device may not operate in conditions exceeding these
limits. The device should be stored at -20°C~70°C with up to 80% RH. In
order to ensure testing accuracy and safety, avoid installing the device
anywhere it would be exposed to direct sunlight, extreme heat, extreme
humidity, vibration frequencies, dust, or unstable power grids.
Section 1.10 Emergency Measures
Switch off the power supply and disconnect the power supply cable in the
event of electrical shock, test item combustion and device combustion.

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Chapter 2 Foreword
Section 2.1 Features
1. 0.1% Base Accuracy, Up to 160% AC Voltage Range, Current Crest
Factor (cf) Settings of 3 or 9. CF3: Up to 215%AC Current Range; CF9:
Up to 645% AC Current Range; CF3: Up to 344% Power Range; CF9: Up
to 1,032% Power Range.
2. With Erp Lot6 2013 Standby and off-mode power loss Standby Power
Consumption Gauge.
3. Continuous Sampling design; AC 50HZ/60HZ base sampling rate of
100KSPS/120KSPS; Standby Power Consumption Gauge Precision of up
to 0.001W for compatible high/low frequency electronic products.
4. Measures: AC/DC voltage current, active power (W), variance (var),
apparent power (VA), power factor (PF), VI angle (DEG), voltage current
crest factor (CF), voltage and current frequencies (Hz), voltage
peak-to-peak (VP-P), current peak-to-peak (IP-P), total harmonic
distortion (THD), harmonic voltage/current analysis at any one of 50
stages, instantaneous current and more.
5. Double CPU Design for Faster Measurements.
6. Easy-to-use Operating Panel.
7. Fast Automatic Transmission - 1 range/0.02 sec @ 50Hz.
8. Current Measuring Circuit utilizes a highly reliable vehicle relay design
and features a long service life.
9. Total harmonic/single-stage distortion can be measured at up to 50
stages.
10. Can connect high-amperage current transformers to measure large
currents
11. Fast and Accurate Measurements.
12. Can connect standard RS232/GPIB cables (one at a time).
13. Suitable for both large and small power measurements and can measure
0.1W standby consumption with analysis precision of 0.001W.
14. High-capacity built-in memory capable of recording 1,000 units of
measurement data for long-term power analysis over time.
15. Comes with voltage meter micro-consumption adjustments.

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Section 2.2 Measuring Functions
Parameter Scope
Testing Scope
Vrms/Vdc
0.1V~800V
Irms/Idc
0.2mA~20A
W
0.01W~16KW
PF
0.0000~±1.0000
Deg
-180.00~+180.00
THD
0.01%~999.99%
Hz
15Hz~100kHz
Section 2.3 Function Flow-Chart
7120 Internal Flow Chart:
7120 Voltage channel input resistance is 1M ohm, voltage can be input
directly for testing or measured with a standard attenuation sonde. Current
measurement terminal uses 0.0025Ω and 0.25Ω precision shunts to directly
measure currents between 0.0002A-20A, and an external CT can be used to
measure larger currents. Measurement and sampling processes use
independent digital signal processors and measurement results are saved in a
dual-port memory before being transmitted to the LED 7-stage display panel by
the CPU, integrated, and applied via the GPIB/RS-232 andATE systems.
ADC
ISO
ZERO phase
Cross monitor
MUX
2.5mΩ
250mΩ
ADC
ISO
ZERO phase
Cross monitor
Dual port
Memory
Black Fin
DSP LPC 4088 CPU
GPIB RS232
KEY 7-Seg.
LED
I+
I-
V+
V-
1MΩ
ADC
ISO
ZERO phase
Cross monitor
MUX
2.5mΩ
250mΩ
ADC
ISO
ZERO phase
Cross monitor
Dual port
Memory
Black Fin
DSP LPC 4088 CPU
GPIB RS232
KEY 7-Seg.
LED
I+
I-
V+
V-
1MΩ

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Chapter 3 Wiring
Section 3.1 Connecting to the Power Supply and
Testing Items
Match the colors on the terminals on the back panel to those of the
terminals above the jigs on the F71201 Test Box to connect the wires and
connect two AC power supply cables - 1 to the F71201, and one to the input
port on the 7120 Power Supply.
Plug appearances in different countries may make it necessary to use a
converter to connect the cable to the F71201 Text Box; please select an
appropriate converter for your locale.

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Section 3.2 F71201-Exclusive Jig Internal Measuring
Wiring Schematic Diagram
Below is a schematic diagram of the internal wiring when using the F71201
Test Box. When the switch is set to 1 the voltage measurement point will be
closer to the testing item to prevent overly low wattage measurements
resulting from voltage drops across the wiring circuit under large currents.
When the switch is set to 2 all power expended by the 7120 voltage input
internal resistor 1M Ω is subtracted from the power rate closest to 0W; this
setting is used only for measuring standby power. Determine whether to set
the switch to 1 or 2 by looking at the rate of the current of the testing object.
I+I- V+V-
Fuse
Fuse
N
LL
N
2
1 SOURCELOAD
Voltage pick up
point
I+I- V+V-
Fuse
Fuse
N
LL
N
2
1 SOURCELOAD
Voltage pick up
point
Caution:
Double check that the voltage and wiring at the
current input terminals are correct before connecting
to mains power to prevent power overload.

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Chapter 4 Operating Settings
Section 4.1 Measurement Mode
Keys:
Steps:
Press
Description:
Indicator
Voltage
Current
RMS
Measured true rms value
Measured true rms value
V-MEAN
Rectified mean value
calibrated to the rms value
Measured true rms value
DC
Measured DC value obtained
by averaging input signal
Measured DC value obtained
by averaging input signal
Harmonic
Measured harmonic distortion
Measured harmonic distortion

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Section 4.2 Measurement range
Keys:
Steps:
Set Voltage range
1. VOLTAGE 2. ↑↓ Select 10V/30V/100V/300V/600V/AUTO 3. ENTER/HOLD
to complete voltage range selection.
Set Current Range
4. CURRENT 2. ↑↓ Select 0.01A/0.03A/0.1A/0.3A/1A/3A/10A/20A/AUTO
then press 3. ENTER/HOLD to complete current range selection.
Description:
The AUTO RANGE LED on the panel will light up when voltage or current
range are set to AUTO. Press the voltage or current key to show which
automatically selected voltage or current range is currently being used by the
device on the C Display.
1.
2.
3.
4.

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Section 4.3 Averaging
Keys:
Steps:
1.SETUP↑↓AVG2.ENTER/HOLD3.↑↓ON/OFF/FACT
2.ENTER/HOLD3.↑↓LIN8/16/32/64/EP8/EP16/EP3/EP64 
2.ENTER/HOLD
Description:
An exponential average (EP8~EP64) is calculated using the following formula:
D = Dn-1 + (Mn–Dn-1)/K
Where
Dn: the value at the nth display;
Dn-1: the exponentially averaged value at the n-1th display;
Mn: the measurement value at the nth display;
K: attenuation constant
A moving average is calculated using the following formula:
D = (Dm-1)+(D m-2)…(D m-64)/m
Where
Dm-(1~64): the moving averaged value at the m-(1~64)th display;
m = 8, when setting LIN8
m = 16, when setting LIN16
m = 32, when setting LIN32
m = 64, when setting LIN64
m: sample number
1.
2.
3.

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Section 4.4 Update Rate
Keys:
Steps:
1. SETUP 2. ↑↓URATE 3. ENTER/HOLD 2.↑↓ 0.1/0.25/0.5/1/2/5
3.ENTER/HOLD
Description:
The update rate defines measurement update intervals: the longer the
period set, the greater the number of sampling cycles, and the more stable the
readings. Each testing item will have its own loading characteristics - slow
down the update rate if the readings show great variation in order to obtain
more stable readings. Sampling cycles for each URATE can be found below.
In Harmonics mode, the update rate can be between .025S~5S.
AC
0.1s
0.25s
0.5s
1s
2s
5s
50Hz Mains
Power
5
10
25
50
100
250
60Hz Mains
Power
6
12
30
60
120
300

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Section 4.5 Synchronization
Keys:
Steps:
1. SETUP 2.↓↑ Select SYNC 3. Press ENTER/HOLD and use ↓↑ to select
V/A/AUTO/OFF
3. ENTER/HOLD
Description:
A: First use the current (with a frequency jitter of under 2%) as a
synchronization source, then the voltage. If both are unstable, take a fixed
sample at 200KSPS.
V: First use the voltage (with a frequency jitter of under 2%) as a
synchronization source, then the current. If both are unstable, take a fixed
sample at 200KSPS.
Auto: Automatically determine whether to use the voltage or the current as the
synchronization source (voltage >1V / Current (only use if reading >3% of
ranges). Automatic Synchronization Source Rules: Synchronize using voltage
only when voltage is stable. Synchronize using current only when current is
stable. Select the lower-frequency option if both current and voltage meet
minimum signal conditions with a jitter of less than 2%. Use a fixed 200KSPS
sample if neither the current nor voltage meets the required conditions. The
current automatic synchronization locked source will be display beneath the
Sync menu as V-Auto (voltage),A-Auto (current) or d-Auto (default fixed
sample). Only RMS/MEAN/DC are supported inAuto mode; in Harmonic mode
please set a stable and lower-frequency signal source as the base frequency.
1.
2.
3.

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Voltage >1V && Voltage Frequency Jitter < 2%
V-Sync
V-Auto
Current > 3% of range && Voltage Frequency Jitter < 2%
A-Sync
A-Auto
OFF: The Sync OFF option is only for capturing high-frequency surge currents.
The 7120 takes fixed ~200KSPS samples and uses different update rates to
calculate the samples. Reading stability has been reaching once the input
signals match the frequencies given in the following table at the completion of
the sampling cycle (pale blue cells); although the pink cell values also indicate
a stable reading frequency, they are only given for reference purposes as their
sampling cycle is just over half a cycle.
Update Rate (Seconds)
Freq.
0.1
0.25
0.5
1
2
5
10
15
1.5
3.75
7.5
15
30
75
150
16
1.6
4
8
16
32
80
160
17
1.7
4.25
8.5
17
34
85
170
18
1.8
4.5
9
18
36
90
180
19
1.9
4.75
9.5
19
38
95
190
20
2
5
10
20
40
100
200
21
2.1
5.25
10.5
21
42
105
210
22
2.2
5.5
11
22
44
110
220
23
2.3
5.75
11.5
23
46
115
230
24
2.4
6
12
24
48
120
240
25
2.5
6.25
12.5
25
50
125
250
26
2.6
6.5
13
26
52
130
260
27
2.7
6.75
13.5
27
54
135
270
28
2.8
7
14
28
56
140
280
29
2.9
7.25
14.5
29
58
145
290
30
3
7.5
15
30
60
150
300
31
3.1
7.75
15.5
31
62
155
310
32
3.2
8
16
32
64
160
320

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33
3.3
8.25
16.5
33
66
165
330
34
3.4
8.5
17
34
68
170
340
35
3.5
8.75
17.5
35
70
175
350
36
3.6
9
18
36
72
180
360
37
3.7
9.25
18.5
37
74
185
370
38
3.8
9.5
19
38
76
190
380
39
3.9
9.75
19.5
39
78
195
390
40
4
10
20
40
80
200
400
41
4.1
10.25
20.5
41
82
205
410
42
4.2
10.5
21
42
84
210
420
43
4.3
10.75
21.5
43
86
215
430
44
4.4
11
22
44
88
220
440
45
4.5
11.25
22.5
45
90
225
450
46
4.6
11.5
23
46
92
230
460
47
4.7
11.75
23.5
47
94
235
470
48
4.8
12
24
48
96
240
480
49
4.9
12.25
24.5
49
98
245
490
50
5
12.5
25
50
100
250
500
51
5.1
12.75
25.5
51
102
255
510
52
5.2
13
26
52
104
260
520
53
5.3
13.25
26.5
53
106
265
530
54
5.4
13.5
27
54
108
270
540
55
5.5
13.75
27.5
55
110
275
550
56
5.6
14
28
56
112
280
560
57
5.7
14.25
28.5
57
114
285
570
58
5.8
14.5
29
58
116
290
580
59
5.9
14.75
29.5
59
118
295
590
60
6
15
30
60
120
300
600
Appropriate Synchronization Sources result in Stable Readings:
The 7120 can be operated in both ordinary power mode and as an
independent ammeter, an ampere-hour meter or an independent voltmeter.
The following table gives synchronization source settings for common input
signals with a description of the synchronization rules of the 7120 in order to
help the user select the most appropriate synchronization source to obtain a
stable and accurate voltage/current/watt reading.

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RMS / DC / MEAN Power Meter Mode
Voltage
Current
Sync-V
Priority Order
(V-A-d)
Sync-A
Priority Order
(A-V-d)
Sync-Auto
(Voltage over
1V, Current over
Gear 3%)
Sync - OFF
The below are actual operating mechanisms for internal
synchronization sources.
Ο(Stable)
Χ(No Freq or Unstable)
V
V
V-Auto
d(default)
No
synchronization
source, use
fixed sampling
rate
Ο(Stable)
Ο(Stable)
V
A
Prioritize those
with long
periodic signals
and jitter <2%.
Χ(Unstable)
Ο(Stable)
A
A
A-Auto
Χ(Unstable)
Χ(No Freq or Unstable)
d(default)
d(default)
d-Auto
Harmonic Power Meter Mode
Voltage
Current
Sync-V
Selected
Only V
Sync-V
Selected
Only V
Sync-Auto
(Voltage over
1V, Current over
Gear 3%)
Sync - OFF
The below are actual operating mechanisms for internal
synchronization sources.
Ο(Stable)
Χ(No Freq or Unstable)
V
No
Measurement
V-Auto
Setting does
not exist
Ο(Stable)
Ο(Stable)
V
A
Prioritize those
with long
periodic signals
and jitter <2%.
Χ(Unstable)
Ο(Stable)
No
Measurement
A
A-Auto
Χ(Unstable)
Χ(No Freq or Unstable)
No
Measurement
No
Measurement
No
Measurement