ITech IT9121 Series User Manual

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Power meter

IT9121 Series User Manual

Model: IT9121 Version:V1.4

IT9121 User Manual

Notices

No part of this manual may be reproduced in any form or by any means (including electronic stor age and retrieval or translation into a foreig n language) without prior permission and written consent from Itech Electronic, Co., Ltd. as governed by international copyright laws.

Manual Par t Number

IT9121-402145

Revision

Edition: June 27, 2017

Itech Electronic, Co., Ltd.

Trademarks

Pentium is U.S. registered trademarks

of Intel Corporation.

Microsoft, Visual Studio, Windows and MS Windows are registe red trad em arks of Microsoft Corporation in the United States and/or other countries and regions.

Warranty

The materials contained in this document are provided “as is”, and is subject to change, without prior notice, in future editions. Further, to the maximum extent permitted by applicable laws, ITECH disclaims all warrants, either express or implied, with regard to this manual and any information contained herein, including but not limited to the implied warranties of merchantability and fitness for a particular purpose. ITECH shall not be held liable for errors or for incidental or indirect damages in connection with the furnishing, use or application of this document or of any information contained herein. Should ITECh and the user enter into a separate written agreement with warranty terms covering the materials in this document that conflict with these terms, the warranty terms in the separate agreement shall prevail.

Technol ogy Licenses

The hardware and/or software described herein are furnish ed under a license and may be used or cop ied only in accordance with the terms of such license.

Restricted Rights Leg end

U.S. Government Restricted Rights. Software and technical data rights granted to the federal government include only those rights customarily provided to end user customers. ITECH

provides th is custo mary comme rcial license in software and technical data pursuant to FAR 12.211 (Technical Data) and 12.212 (Computer Software) and, for the Department of Defense, DFARS

252.227-7015 (Technical Data – Commercial Items) and DFARS

227.7202-3 (Rights in Commercial Computer Software or Computer Software Documentation).

Safety Notices

A CAUTION sign denotes a hazard. It calls attention to an operating procedure or practice that, if not correctly performed or adhered to, could result in damage to the product or loss of important data. Do not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met.

A WARNING sign denotes a hazard. It calls attention to an operating procedure or practice that, if not correctly performed or adhered to, could result in personal injury or death. Do not proceed beyond a WARNING sign until the indicated conditions are fully understood and met.

NOTE A NOTE sign denotes important hint. It calls attention to tips or supplementary information that is essential for users to refer to.

IT9121 User Manual

Quality Certification and Assurance

We certify that T9121 power m eter meets al l the published specifications.

Warranty

ITECH warrants that the product will be free from defects in material and workmanship under normal use for a period of one (1) year from the date of delivery ( except those described in the Limi tation of Warranty below).

For warranty service or repair, the product must be r eturned to a s ervice center designated by ITEC H.

 The product returned to ITECH for warranty service must be shipped PREP AID.

And ITECH will pay for return of the product to customer.

 If the product is returned to ITECH for warranty service from overseas, all the

freights, duties and other taxes shall be on the acc ount of customer.

Limitation of Warranty

This War ranty will be rendered invalid if the product is:

 Damage d resulting from cus tom er-wired circuits or customer-supplied parts or

accessories;

 Modified or repaired b y customer without authorization;  Damage d resulting from cus tom er-wired circuits or use in an envi ronment not

designated by us;

 The product model or serial number is altered, deleted, removed or made

illegible by customer;

 Damaged as a result of accidents, includi ng but not limited to lightning,

moisture, fir e, improper use or negligence.

Safety Symbols

Direct current

ON (power)

Alternating current

OFF (power)

Both direct and alternating current

Power-on state

Protective earth (ground)

terminal

Power-off state

Earth (ground) termi nal

Reference terminal

Caution

Positive terminal

Warning (refer to this manual for specific Warning or Caution informati on)

Negati ve terminal A chassis terminal

IT9121 User’s Manual

Safety Precautions

The following safety precautions must be observed during all phases of operation of this instrume nt. Failure to comply with these pr e cautions or speci f i c warnings elsewhere in this manual will constitute a default under safety standards of design, manufacture and intended use of the instrument. ITECH assumes no l iability for the custom er’ s failure to comply with these preca utions.

 Do not use the instrument if it is damaged. Before operation, check the

casing to see whether it cracks or is not appli ed w ith suf ficient plastics. Do not operate the instrum ent in the pr esence of inflammable gasses, vapor s or dusts.

 The max imum operating voltage and current of the inst rument are 600V

and 20A respectively. Exceeding these limits will l ead to burnout of the instrument.

 Make sure to use the power cord supplied by ITECH.  Check all marks on the instrument before connecting the instrument to

power supply.

 Tur n off the instrument and the operation system before connecting to the

I/O terminal.

 Do not use the instrument if t he detachable cover is remo ved or loosen.

 Do not connect the instrument to any cable or terminal block bef ore

self-testing.



To prevent the pos sibility of accidental injuries, be sure to use the power adapter supplied by the manufacturer only.

 We do not accept responsibility for any direct or indirect financial damag e

or loss of pr ofit that might occur when using the instrument.

 This instrument is used for industrial purposes. Do not apply t his product to

IT power supply system.

 Never use t he i nst rum ent with a life-support syst em or any ot her equi pment

subject to saf ety requirements.

 Fail ure to use the instrument as directed by the manufacturer may render

its protective features void.

 Always clean the casing with a dry cloth. Do not clean the internals.

 Make sure the vent hole is always unblocked.

Environmental Conditions

The instrum ent is designed for indoor use and an area with low condensation. The table below shows the general environmental requirements for the instrument.

Enviro nmental Cond iti ons

Requirements

Operating tem perature

5°C-40°C

Operating humidity

humidity 20%-80% (non-condensation)

Storage temper ature

-20°C-50 °C

Altitude

Operating up to 2,000 meters

IT9121 User’s Manual

Install ation category

Polluti on degree

Polluti on degree 2

NOTE

To m ake accurate measurements, allow the instrument to warm up for 30 min.

Regulatory Markings

The CE mark indicates that the product complies with all the relevant European

legal

directives. The specific year (if any) affixed refers to the year when the design was approved.

The instrum ent complies with the WEEE Directive (2002/96/EC) marking requirement. This affix product label indicates that you must not discard the

electrical

/electronic product in domestic

househol d waste.

This symbol indicates the time period during which no hazardous or toxic substances are expected to leak or deteriorate during normal use. The expected useful life of the product is 10

years. The product

can be used safely

during the 10-

year Environment Friendly Use Period (EFUP). Upon expiration of the EFUP, the product must be immediately recycled.

Waste Electrical and Electronic Equiment (WEEE) Directive

2002/96/E C Waste Electrical and El ectronic Equipment

(WEEE) Directive

This product complies with the WEEE Directive (2002/96/EC)

marking requirement. Thi s affix product label indicates that you must not discard the el ectrical/electronic product in domestic

househol d waste.

Product Category

With

reference to the equi pment classifications described in the

Annex 1 of the WEEE Directive, this instrument is classified as a “Monitoring and Control Instr ument”.

To return thi s unw anted instrument, contact your ne ar est I TE CH office.

IT9121 User’s Manual

Compliance Information

Complies with the essential requirements of the following applicable European Directives, and carries the CE marking accordingly:

 Electromagnetic Compatibility (EMC) Directive 2014/30/EU  Low-Voltage Directive (Safety) 201 4/35/EU

Conforms with the following product standards:

EMC Standard

IEC 61326-1:2012/ EN 61326-1:2013 ¹²³

Reference Standards

CISPR 11:2009+A1:2010/ EN 55011:2009+A1:2010 (Group 1, Class A)

IEC 61000-4-2:2008/ EN 61000-4-2:2009

IEC 61000-4-3:2006+A1:2007+A2:2010/ EN 61000-4-3:2006+A1:2008+A2:2010

IEC 61000-4-4:2004+A1:2010/ EN 61000-4-4:2004+A1:2010

IEC 61000-4-5:2005/ EN 61000-4-5:2006

IEC 61000-4-6:2008/ EN 61000-4-6:2009

IEC 61000-4-11:2004/ EN 61000-4-11:2004

1. The product is intended for use in non-residential/non-domestic environments. Use of the product in residential/domestic environments may cause electromagnetic interference.

2. Connection of the instrument to a test object may produce radiations beyond the specified limit.

3. Use high-performance shielded interface cable to ensure conformity with the EMC standards listed above.

Safety Standard

IEC 61010-1:2010/ EN 61010-1:2010

IT9121 User’s Manual

Content

Quality Certification and Assurance ....................................................................................................................... 1

Warranty ............................................................................................................................................................... 1

Limitation of Warranty .......................................................................................................................................... 1

Safety Symbols ...................................................................................................................................................... 1

Safety Precautions ................................................................................................................................................. 2

Environmental Conditions ..................................................................................................................................... 2

Regulatory Markings ............................................................................................................................................. 3

Waste Electrical and Electronic Equiment (WEEE) Directive ................................................................................... 3

Compliance Information ........................................................................................................................................ 4

Chapter1 Introduction ..................................................................................................................................... 1

1.1 Brief Introduction ............................................................................................................................................ 1

1.2 Introduction of front panels............................................................................................................................. 2

1.3 Introduction to keyboard ................................................................................................................................. 2

1.4 Introduction of Menu Function........................................................................................................................ 3

1.5 Introduction of Interface Display Information .................................................................................................. 5

1.6 Introduction of Interface Symbols.................................................................................................................... 5

1.7 Introduction of rear panels .............................................................................................................................. 6

Chapter2 Measurement Conditions ................................................................................................................. 7

2.1 Setting of Measurement Range ....................................................................................................................... 7

2.2 Setting of Measurement Interval ..................................................................................................................... 9

2.3 Setting of Filter and Crest Factor .................................................................................................................... 11

2.4 Setting of Averaging Function ........................................................................................................................ 12

Chapter3 Basic Measurement Functions ....................................................................................................... 15

3.1 Basic Concepts .............................................................................................................................................. 15

3.2 Setting of Measurement Function and Interface Display ................................................................................ 16

Chapter4 Waveform Display Function ........................................................................................................... 18

4.1 Basic Concepts .............................................................................................................................................. 18

4.2 Adjustment of Measurement Parameters ...................................................................................................... 21

4.3 Setting of Trigger Configuration ..................................................................................................................... 21

Chapter5 Integral Operation Function ........................................................................................................... 23

5.1 Basic Concepts .............................................................................................................................................. 23

5.2 Setting of Integral Measurement Configuration ............................................................................................. 27

5.3 Integration..................................................................................................................................................... 29

Chapter6 Harmonic Measurement Function .................................................................................................. 32

6.1 Basic Concepts .............................................................................................................................................. 32

6.2 Setting of Harmonic Measurement Configuration .......................................................................................... 35

Chapter7 Routine Maintenance ..................................................................................................................... 38

7.1 Self-inspection ............................................................................................................................................... 38

7.2 Error Information References ........................................................................................................................ 38

7.3 Daily maintenance ......................................................................................................................................... 40

7.4 Contact of ITECH Engineers............................................................................................................................ 40

Chapter8 Technical Specifications .................................................................................................................. 42

8.1 General Specification ..................................................................................................................................... 42

8.2 Screen Display ............................................................................................................................................... 42

8.3 Input Parameters ........................................................................................................................................... 42

8.4 Voltage and Current Accuracy ........................................................................................................................ 44

8.5 Active Power Accuracy .................................................................................................................................. 44

8.6 Voltage Current and Power measurements.................................................................................................... 45

8.7 Frequency Measurement............................................................................................................................... 47

8.8 Harmonic Measurement ................................................................................................................................ 47

IT9121 User’s Manual

8.9 Fundamental Frequency ................................................................................................................................ 48

8.10 Accuracy ...................................................................................................................................................... 48

8.11 Oscilloscope Function .................................................................................................................................. 49

8.12 Interface Specification ................................................................................................................................. 49

Introduction

Chapter1 Introduction

1.1 Brief Introduction

The IT9121 power meter can provide the maximum input of 600Vrms and 20Arms and the measurement bandwidth of 100KHZ and thus can be easily used for measuring the parametersincluding voltage, current, power, frequency and harmonics. Standard configuration includes USB, GPIB, RS232 and LAN communication interfaces and also the interface for USB peripherals. The user can store the measured parameters in the external storage medium. The voltage and current precision is 0.1%. The instrument also has many integral functions, such as the active power. The product can be widely applied in motors, household appliances, UP S and other test fields.

Features

 4.3-inch color liquid crystal displ ay (TFT)  The number of matrix columns to be displayed on the screen and the

commonly used measurement parameters can be set freely.

 Input range:600Vrms/20Arms  The voltage, current, power, harmonics and other parameters can be

measured at the same time.

 The precision of voltage and current m easurement is up to 0.1%.  It has the harmonic measuring function and can measure 50-order

harmoni c components at most.

 With the interface for USB peripherals, the user can store the interface in

the external storage medium.

 With many powerful integral functions, the bought/sold electricity can be

calculated.

 Frequency me asurement function  Built-in USB, GPIB, RS232 and LAN communication interfaces

Application advantages

 Analysis of UPS power quality:

As an important backup power supply in the communication industry, the steady-state characteristics, dynamic characteristics, power quality and other parameters of UPS should be analyzed. With internal nonlinear elements, the UPS power supply will generate a large number of harmonic components during operation, which may affect operation of the communication system. The IT9121 power meter can measure such parameters as the AC/DC signal, power factor, harmonics, frequency and distortion factor, and systematically and comprehensively analyze the performance of the UPS power supply.

 Test of performance of household appliances:

With promotion of the concept of using energy in a rational and environmentally friendly manner, more and more household appliances adopt the variable frequency control technology to reduce the power consumption. The IT9121 power meter can measure the inrush current, active power, crest factor, etc.

Introduction

1.2 Introduction of front panels

Schematic Diagram of Front Panel of IT9121 Series Power Meter and Diagram of Key Functions.

1 USB Interface

2. Displ ay

3. Menu key

4. Waveform Display key

5 Basic fu nctions

6. Harmonic key

7. Integrator key

8. Setting knob

9. Arrow keys

10. Hold/Esc key

11. Enter key

12. Image Save key

13 Parameter setting key

14. Menu key

15 Power switch

1.3 Introduction to keyboard

The functions of keys on the front panel of the IT9121 series power meter are shown in the following table.

Key tag

Name and funct ion

Waveform Display key When this key is pressed,the waveform corresponding to current measurement data will be displayed.

Harmonic Measurement key When this key is pressed, the harmonic measurement results and the menu of harmonic measurement parameter configuration will be displayed.

Basic Measurement key When this key is pressed, the measurement data of various it ems w ill be displayed.

Integral Measurement key When this key is pressed, the integral measurement results and the menu of integral measurement parameter configuration will be displayed.

Menu key, used for setting relevant measurem ent parameters of the power met er.

Enter key, used for savi ng the settings.

Image Save key

Cancel/E SC key The front panel keyboard can be locked/unlocked when the ESC

key is constant ly pressed for 5s.

The remote control m ode of the power meter can be switched to

the panel operation mode when

the ESC key is constantly

pressed for 5s.

Introduction

Key tag

Name and funct ion

Up/Down key and Left/Right key

List Edi t: t hose l i nes w hich are not displayed c an be di spl ay ed by operating t he Left /R i ght key. Those rows w hi ch are not di spl ay ed

can be displayed by operating the Up/Down key.

Menu Edit: the programming items can be rolled by operating the Up/Down key. Prompts of corresponding options are displayed on the right and options can be selected v ia the soft

key.

Digit Edit: the programming items can be rolled by operating the

Up/

Down key. The digit to be edited is selected by operating the Left/Right key or via the knob. Carrying can be completed automatically.

Soft key The contents on the left of the key and the menu

function displayed above the key on the display screen may be

subject to changes.

Knob key, used for setting the value indicated by the cursor, selecting the voltage and current range, adjusting the waveform, etc.

1.4 Introduction of Menu Function

Press this key to enter the system menu function. Menu is described as follows.

Menu setting

SYSTEM

SYSTEM INFO

Instrument system information

Model

Instrument model

Serial

Instrument SN

Cpu Version

The version of CPU

Dsp Version

The version of Digital Sig nal Processing

MAC address

Network hardware address

Socket Port

Port number

COMM CONFIG

Communication

configuration

R232

BAUD Rate

Set the communication baud rate:4800/9600/19200/38400/57600/115200

Parity Chack

Communication parity check bit: Default: NONE

Data bit

Communication data bit: 8 (default)

Stop bit

Communication st op bit : 1 (default)

USB T y pe B Conne ct

Select the USB communicat ion interface.

GPIB GPIB Address

The address is adjustable between 1 and 30.

LAN

IP mode

IP mode: MANU/DHCP

IP Addre ss

IP address setting

Subnet mask

Set the subn etmask.

Gateway

Set the gateway.

Introduction

SYSTEM CONFIG

System conf iguration

Date (YY/MM/DD)

System date: Year/Month/Day

Ti me (hh:mm:ss)

System time: Hour/Minute/Second

Brightness

Set the screen brightne ss.

Beep

Set the keyboard sound

SELF TEST

Self test

SYSTEM SELF_T EST

Self test

INITIAL

Initialize

SYSTEM INITIAL

System initialization

SETUP

SETUP INFO

Configuration information

Averag

Average

Sync Source

Synchronization

Line Filt er

Line fil ter

Update Rate

Data updating rate

Freq Filter

Frequency filter

Crest Factor

Crest factor

ExSensor1

External current sensor 1 (range: CF=3:2.5V,5V,10V; CF=6:1.25V, 2.5V,5V.)

ExSensor2

External current sensor 2 (range:

CF=3:50mV,100mV,200mV,500mV,1V,2V;

CF=6:25 mV,50mV,100mV,250mV,0.5V,1V.)

Rate(V/A)

Conversion ratio of external cur rent sensor 1

Rate(mV/A)

Conversion ratio of external cur rent sensor 2

U_Range

Voltage range

I_Range

Current range

AVERAG SET

Average f unction setting

State

Status

Mode

Type

Loading Type

Count

Counti ng cycle

EXT SEN SET

External current sensor setting

EXSENSOR 1

Set the external current sensor 1: ON/OFF

Ratio(V/A)

Set the con version ratio of the external current sensor 1

EXSENSOR 2

Set the external current sensor 2: ON/OFF

Ratio(mV/A)

Set the con version ratio of the external current sensor 2

OTHER SET

Other settings

Sync Source

Select the synchroni zation source: U/I/OFF

Freq Filter

Set the frequency filter: ON/OFF

Line Filt er

Set theline filter : ON /OFF

Crest Factor

Set the crest factor: CF3/CF6

Update Rate

Set the data updating rate:

0.1s/0.25s/0.5s/1s/2s/5s

INRUSH SET

Inrush sett ing

Introduction

State

Status

Trig le vel(A)

Trigger level

Delay time(ms)

Delay time

Measure time(s)

Measuri ng time

CAL ZERO

Calibration Zero

Zero point calibration

Calibration Zero

Zero point calibration

1.5 Introduction of Interface Display Information

The IT9121 power meter has four measurement modes. Below is the introduction of basic interface information, with the basic measurement interface as an example.

Basic measurement interface

Select the “Meter” button, and the initial interface of basic measurement as shown bel ow will appear.

1.6 Introduction of Interface Symbols

The interface of the IT9121 power meter will display the following symbols.

Status Bar icon

Status descri ption

This icon appears when the line filter is

switched on.

This icon appears when the frequency filter is

switched on.

This icon appears when USB is insert ed.

Over-voltage protection icon: this icon appears

when over-voltage occurs.

Over-current protection icon: this icon appears

when over-current occurs.

Introduction

Status Bar icon

Status descri ption

Key Lock: this icon appears when the keyboard

is locked.

Remote Lock: this icon appears in remote

operation and then local keys fail.

This icon appears in remote network

connection.

1.7 Introduction of rear panels

Schemati c D iagram of Rear Panel of IT9121 Power Meter.

1. GPIB interface

2 Ethernet interface

3 USB Interface

4. RS232 i nterface

5. External synchronization signal interface

6 Power i nterface

7. External sensor interface

8. Voltage input terminal

9. Current input terminal

Warning: The external sensor interface (as shown in Fig. 7 above) of IT

9121 power meter is installed with a protective jacket at ex-factory, which should be correctly installed at all circumstances unless an external sensor permitted by ITEC H is used.

Measurement Conditions

Chapter2 Measurement Condi t i ons

This chapter describes details of relevant work to be finished before use of the IT9121 power meter.

2.1 Setting of Measurement Range

The appropriate measurement range (v oltage and current range) must be set for accurate measurement. The selected range is effective for different measurement modes, such as waveform display, integral measurement and harmoni c me asurement.

Operation steps

1. In the “Meter” interface Press the soft key corresponding to “V-RANGE” or “A-RANGE”, and us e the knob or “ ” to select the voltage or current

range.

2. Press the “Enter” key to confirm the setting. The instrument will automatically confirm and exit the setting in case of no operation on the interface for more than 5s.

 When the crest factor is 6:

Figure: Voltage Range

Figure: Current Range

Measurement Conditions

 When the crest factor is 3:

Figure: Voltage Range

Figure: Current Range

NOTE

When EX1 or EX2 is installed, the power meter has more current range options. See details in IT9121 Installation Instructions.

Voltage and current range

Set the measurement range according to the lev el of the effective value. When the voltage or current signal is input into the input unit, there are two types of range: fixed and automatic.

Fixed range

Select the required range from a number of options. After selection, the range will not change with the input signal. For the voltage range, when the crest factor is 3, the maximum option is “600V” and the minimum option is “15V”. When the crest factor is 6, the maximum option is “300V” and the minimum option is “7.5V”.

Measurement Conditions

NOTE

During measurement of the distortion waveform and other non-sinusoidal wave signals, the accuracy of measurement can be improved by selecting the minimum range on the premise that the measured value does not exceed the range.

Auto-measuring span

The range is switched automatically according to the input signal. The range types for switching are the same as those of the fixed range.

Principles of automatic range l evel increase: The range level is increased when any one of the following conditions is

satisfied.

 Urms or Irms exceeds 110% of the current range setting.  The crest fa ct or is 3. The value Upk or Ipk of t he i nput si gnal ex cee ds 33 0%

of the current range setting.

 The crest factor is 6. The value Upk or Ipk of the input signal exceeds 660 %

of the current range setting.

Principles of automatic range l evel decrease: The range level is decreased when all of the following conditions are satisfi ed.  Urms or Irms is less than or equal to 30% of the current measurement

range.

 The crest factor is 3. The v alue Upk or Ipk of the input signal is less than

300% of the ra nge at the following l evel.

 The crest factor is 6. The v alue Upk or Ipk of the input signal is less than

600 % of the ran ge at the following l evel.

NOTE

The selected automatic range may change when the input waveform is a pulse waveform of uncertain cycle. In this case, the fi xed range should be selected.

2.2 Setting of Measurement Interval

The time for acquisition of sampling data is determined by the measurement interval during measurement. The measurement interval is determined by the data updating rate and synchronization source. The synchronization source provides reference signals for measurement, and the data updating rate determines the updating cycle of sampling data.

Measurement interval

The measurement interval is determined by the data updating rate and synchronization source. (see “2.3 Setting of Filter and Crest Factor” for specific settings)

 Synchronization

IT9121 adopts the frequency measurement circuit to t est the input signal cycle set in the measurement interval. The measurement inter val is the integer times of the test cy cle. The measured value of IT9121 is calculated by averaging sampli ng data in the measurement i nterval. The reference input signal used for defining the input signal measurement interval is called the synchronization source.

 Measurement inter val for conventional measurement

 The measurement interval of the reference input signal is the time fro m the

Measurement Conditions

starti ng part of the rising slope (or descending sl ope) through the zero point (intermediate value of amplit ude) to the ending point of the rising slope (or descendi ng slope) through the zero point (intermediate value of amplitude). However, the measurement int erval which det ermines the maximum voltage or current is within the overall data updating cycle. Therefore, the measurement of Ipk+, I pk-, Upk+, Upk-, Ucf and Icf cal cul ated base d on t he maximum voltage and current also adopts the data updating cycle as the measurement interval.

 The rising or descending edge is selected automatically to prolong the

measurement interval.

 If there i s only one or no rising slope or descending slope wit hin the data

updating cycle, the data updating cy cle is taken as the measurement interval.

 The input signal to be used as the synchronization source can be set in

each unit (for synchronizati on with the zero point of that input signal). The overall interval of the signal voltage, current or data updating cycle can be selected as the synchronization source for mea surement.

NOTE

The data updating cycle refers to the cycle used for calculating sampling data of the measurement function. It is identical to the set value of the data updating rate.

The slope refers to signal changes from low level to high level (rising edge) or from high level to low level (descending edge).

 Measurement interval for harmonic measurement

At the sampling frequency of harmonic m easur e ment , t he meas ure ment i nt erval refers to t he first point 1024 from the data updating cycle. The sampling frequency of harmonic measure me nt is determined automatically by the signal cycle set as t he P LL source in the instrument. The sampling data or measurement interval for calculation may be differ ent from the sampling data or measurement interval of the measur ement function in conventional measurement.

Measurement Conditions

2.3 Setting of Filter and Crest Factor

Operation steps

1. Select Menu > SET UP > OTHER SET and enter the OTHER configuration page.

2. Press to select the param eter to be config ured (bl ue fo nt bac kgr ound), and then press the soft key corresponding to the paramet er on the right to set the required value, as shown in the following diagram.

Character

Function description

Sync Source

Select the synchronization source: U/I/OFF. The overall

interval of the signal voltage, current or data updating cycle

can be selected as the synchronization source for measurement.

Freq Filter

Set the status of the frequency filter. When “ON” is selected, the frequency filter is turned on. When “OFF” is selected, the frequency filter is turned off.

Line Filt er

Set the status of theline filter. When “ON” is selected, the line filter is turned on. When “OFF” is selected, the line filter is turned off.

Crest Factor

Set the crest factor: CF3/CF6

Update Rate

Data Updating Rate Setting key: when this key is pressed, the capture interval of the voltage, current, power and other data, i.e. data updating rate, can be set. When the data updating rate is increased, rapid load changes of the power system can

be obtained. When the data updating rate is decreased, relative low-

frequency signals can be measured. Options of

the data updating rate: 0.1s/0.25 s/0.5s/1s/2s/5s

3. Press the Enter key to save the settings.

Filter

Frequency filter: it is inserted in the frequency measurement circuit and may affect frequency measurement. It can be used for filtering high-frequency components of interference to make the measured frequency parameter more accurate. W hen the frequency filter is switched on, the voltage or current of no more than 200Hz can be mea sured. The cutoff frequency is 500HZ.

Measurement Conditions

Line filter: it is inserted in the voltage and current m easurement circuit and has direct influence on measurement of the voltage, current and power. When the line filt er is swit ched on, noi se and high-frequency component s fr om t he invert er or distortion waveform can be fil tered. The cutoff frequency is 500HZ.

Crest factor

The crest factor is the ratio of the waveform peak to the effective value. The crest factor of IT9121 is specified as the times of the crest value which can be input under the rated input conditions. The crest factor CF3 or CF6 can be selected in the interface “Menu > SETUP > OTHER SET”.

ranget Measuremen

input be can whichPeak value

)(factor Crest =CF

The crest factor can be set as 3 or 6. The crest factor can be measured under the foll ow ing conditions:

{ }

value)(effective valueMeasured

6)or (3 CF of Set valueranget Measuremen

factorCrest

=）（CF

NOTE

The crest value of the input signal must be no more than the maximum allowable input value.

When the crest factor of the measured signal is larger than the crest factor in instrument specifications (based on the crest value of rated input), the signal with the crest factor larger than the specified value can be measured by setting a range including the value of the measured signal.

For example, when CF is set as 3 but the measured value (effective value) is less than 60% of the range, the signal w ith CF more than 5 can be measured.

When CF is 3, the signal with CF equal to 300 can be measured under minimum effective input (1% of the range) conditions.

The voltage range, current range, effective input range and measurement accuracy de pend on the set crest factor.

2.4 Setting of Averaging Function

The user can set the averaging function via this menu. When the input signal frequency is low, the value is displayed unstably and cannot be read easily. In this case, the averaging function can be enabled to calculate and display the average value of several measurements.

Operation steps

1. Select Menu > SET UP > AVERAG SET to enter the configuration page of the averaging function.

2. Press to select the parameter to be configured (blue font background), and then press the soft key corresponding to the parameter on the right to set the required value, as shown in t he followi ng diagram.

Measurement Conditions

Parameter descriptions:

Character

Function description

State Set the status of the averaging function. When “ON” is selected,

the averaging function is enabled. When “OFF” is selected, the averaging function is disabled.

Type

Set the linear averaging type. EXP: index averaging, often used

for analy sis of t he non-st ationary process. LINE: li near averaging,

often used for measurement and analysis of the stationary random process. The deviation relative to the standard can be reduced by increasing the averaging times.

Tcontrol

Set the mode of the averaging function. MOVING: moving averaging R EP EAT: repeate d averaging

Count

Set the times of the averaging function. If the mode of the averaging function is set as EXP (index averaging), the attenuation constant can be set. If the mode of the averaging

function is set as LINE (linear averaging), the averaging times

can be set.

3. Press the Enter key to confir m the setting.

Averaging mode

 Index averaging:

Computing formula:

11−

−

Dn: the value displayed after the nth index averaging (D1, the value displayed after the first averaging, is equal t o M1) Dn-1: the value displayed after the (n-1)th index averaging Mn: the nth measured data. K: attenuation constant (1-64)

 Linear averaging

Computing formula:

( )

MMMM

nnnmn

+++

−−−− 121

....

Dn: the value displayed after linear averaging of m values from the (n-(m-1))th to nth val ue

Measurement Conditions

Mn-(m-1): the (n-(m-1))th measured data Mn-2: the (n-2)th measured data Mn-1: the (n-1)th measured data Mn: the nth measured data. M: the number of average values (1-64) When m can be divided exactly by n, the calculated value is the moving average; when there is no particular relationship between m and n, the calculated value is the repeated averag e.

NOTE

When index averaging is set, averaging is implemented under the harmonic measurement function.

When linear averaging is set, averaging can only be implemented in the conventional measurement function and this mode is not applicable to the harmonic measurement function.

Averaging function

 Measurement function in conventional measurement

The following measurement functions are subject to di rect averaging. Data of the foll owing mea sure ment funct i ons ar e obtained via operation in ot her modes, and the obtained measurement function is affected averaging.

 Urms, Umn, Udc, Urmn, Uac, Irms, Imn, Idc, Irmn, Iac, P, S and Q.  Ucf, Icf, PF and WPAV are calculated by operation of the a veraged Urms,

Irms, P and S.

 Measurement function in harmonic measureme nt

 U(k), I(k), P(k), S(k) and Q(k).  PF(k) is calculated via operation of the average d P(k) and Q(k).  U(%r), I(%r), P(%r) , U(%f), I(%f) and P(%f ) are calculated via operation of

the averaged U (k), I(k) and P(k).

(k indicates t he harm onic t imes.)

NOTE

When the averaging function is enabled, the average of a number of measurements are calculated and displayed. Therefore, in case of drastic changes of the input signal, the measured value will slowly affect these changes.

For both the attenuation constant of index averaging and the number of averaged values of linear averaging, the larger the set value is, the more stable the measured value is.

The following measurement functions will not be affected by averaging. Conventional measurement functions:fU, fI, Ipk+, Ip k-, Upk+, Upk-, Time, WP, WP+,

WP-, q+, q-, q and Fsyn. Harmonic measurement functions: φ(k) , φUU(k) and φII(k) (k indicates the harmonic times).

Basic Measurement Functions

Chapter3 Basic Measurement Funct ions

This chapter describes the features and use of the basic measurement functions of the IT9121 power meter in details.

3.1 Basic Concepts

The IT9121 power meter has rich basic power measurement functions and can be used for accurately measuring the voltage, current, power, AC/DC signal, power factor, harmonics, frequency, distortion factor and other parameters. The reliable data can prov ide a scientific basis for analysis of the power quality and performance of equipment.

Introduction of soft keys on the interface

Menu soft key

Instruction

U-RANGE

Set the voltage range.

I-RANGE

Set the current range.

RUN/HOLD

Running/holding

RESET Reset soft key When this key is pressed, the instrument

can immedi ately carry out measurem ent again.

View (1): displaying 1 large value and 6 small values.

View (4): displaying 4 large value and 6 small values.

View (2): displaying 12 large values.

MAXHOLD (OFF/ON)

Maximum value holding (OFF/ON): the maximum value (MAX) of data can be held.

CONFIG

Basic measur ement configuration

Measured parameters

Parameters

Parameter descriptions

Parameters

Parameter descriptions

Active power [W]

Imn

Average rectified val ue after

the

current is calibrated to

the effective value

Reactive power [var]

Idc

Average current

Apparent power [VA]

Ipk+

Positive current peak value [A]

Power factor

Ipk-

Negative current peak value [A]

Basic Measurement Functions

Parameters

Parameter descriptions

Parameters

Parameter descriptions

Phase difference of voltage and current

Ipp

Current peak-to-peak value [A]

Fsyn

Synchronization source frequency

Icf

Current crest factor Irms

Current effective value [VA]

Current frequency (Hz)

Iac

AC current component

Irush

Inrush current

Irmn

Average rectified current [A]

Urms

Voltage effective value [VA]

Umn

Average rectified value after

the voltage is calibrated to the

effective value

Urmn

Average rectified value of

voltage [V]

Udc

Average voltage [V]

Uac

AC voltage component

Upk+

Positive voltage peak value [V]

Upk-

Negative vo ltage peak va lue [V]

Upp

Voltage peak-to-peak value [V]

Ucf

Voltage crest factor

Voltage frequency (Hz)

3.2 Setting of Measurement Function and Interface Display

The power meter has three interface display styles for measurement of basic parameters. At most five pages are displayed in each style. When one or more important measurement parameter(s) should be highlighted, the View1 or View4 mode can be freely enabled to design the humane display style. W hen you need to view all parameters at the same time in one interface, the View12 mode can be enabled.

Take power measurement as an example. The interface can display four parameters in the large font form: effective voltage, effective current, active power and power factor. Operating procedures ar e as below:

Operation steps

1. In the “Meter” interface when the soft key corresponding to “VIEW 4” is pressed, 10 measurement parameters can be displayed in total, 4 of which are displayed in an amplified manner. Other measurement parameters can

be viewed by pressing key to turn pages, as shown in the figure below.

2. When the soft key corresponding to “CONFIG” is pressed, the measurement function can be selected and the interface display

Basic Measurement Functions

information can be set.

3. W hen the soft key corresponding to “FUNC” is pressed, the measurem ent function can be s elected. For exam ple, when the “FUNC” key is pressed once, the displayed measurement function will be switched once in the W/I/V sequence. Different measurement parameters are displayed when different functions are selected. As power measurement is taken as an example in this operat ion, P is selected.

 P (power): P, Q, S, PF, φ and Fsyn  I (current): Irms, Imn, Irmn, Idc, Iac, Ipk+, Ipk-, Ipp, Icf,

fI and Irush

 U (voltage): Urms, Umn, Urmn, Udc, Uac, Upk+, Upk-, Upp, Ucf and

4. Press the “ ” key and move the cursor to select the parameter displayed in the interface (blue font background). Press the right soft key corresponding to the parameter to adjust the parameter displayed at present. P, Q, S and PFare set in sequence.

NOTE

When the soft key corresponding to the parameter is pressed once, the parameter will be selected in sequence.

5. You can also press the “INSER T PAGE” to add a display page. At most five pages are all owabl e. Press t he “DELET E P AGE” to del ete the di splay page. At least one page should be left.

Waveform Display Function

Chapter4 Waveform Display Function

This chapter describes the features and use of the waveform display function of the IT9121 power meter in details.

4.1 Basic Concepts

The IT9121 power meter has a waveform display function based on sampling data. The voltage and current waveform of the input unit can be displayed or hidden. Only the necessary waveform is displayed to facilitate observation. The wavefor m display interface includes the vertical axis and the horizontal axis.

Introduction of soft keys on the interface

When the button is pressed, the initial waveform display interface below appear s.

Description of information of w aveform display interf ace:

Parameter name

Parameter descriptions

U_RANGE

Voltage range setting: press the soft key corresponding to this parameter to set the voltage range.

I_RANGE

Current range setting: press the soft key corresponding to this parameter to set the current range.

RUN/STOP

Run/stop: press the soft key corresponding to this parameter to run or stop the waveform status.

SINGLE

Single measurement key: when single measurement is performed under stop conditions, the stop status will be enabled again after one

measurement according to the curre

nt data updating rate. When single measurement is performed under running conditions, one measurement will be performed immediately by the instrument and then the stop status will be enabled.

SCOPE(U/I/UI)

Select the waveform to be displayed on the screen: voltage/current/voltage and current.

Waveform Display Function

Parameter name

Parameter descriptions

KNOB SEL

(U/I/TL/TD/Td)

Knob selection: the following variables can be adjusted by rotating the knob: vertical voltage position/vertical current position/trigger level/t rigger delay/level calibration.

AUTO

Automatic adjustment key: when the soft key corresponding to this parameter is pressed, the power meter will automatically calibrate the input signal to display the best effect of t he input signal.

TRIG SET

Trigger setting

MEASURE SET

Measurement setting

Introduction of waveform display interface

The trigger status is described as follows:

Trigger status

Instruction

Auto

When the trigger mode is set as Auto, the trigger status Auto will be di splayed after triggering.

Auto?

When the trigger mode is set as Auto, the trigger status will be

Auto in the case of no triggering?

Trig

When the trigger mode is set as Normal, the trigger status Trig will be di splayed after triggering.

Trig?

When the trigger mode is set as Normal, the trigger status will be Trig in the case of no triggering?

Stop

When the “Stop” soft key in the waveform display interface is pressed, the t rigger status Stop will be displayed.

Vertical calibration

When the crest factor CF is 3, the selected vol tage range and current range will

Waveform Display Function

be subject to vertical calibration (voltage/grid, current/grid). When CF is 6, the selected voltage range and current range will be subject to two-time vertical calibration (voltage/grid, current/grid).

Horizontal calibration

When the “KNOB SEL” soft key is pressed and “T/d” is selected, horizontal calibration (scanning speed) adjusted by rotating the knob. In this case, time/grid information changes can be observed on the screen by rotating the knob and changing the horizontal (time/grid) setting. When acquisition is run, the sampling rate can be changed by adjusting the horizonta l calibration knob. When acquisition is stopped, sampling data can be amplified by adjusting the horizontal calibration knob.

Trigger delay

When the KNOB SEL s of t key is pr essed and “T D” is selected, the trigger delay can be adju sted by rotating the knob. In this case, when the knob is rotated, the trigger point will move horizontally and the delay time will be displayed on the

screen. When the delay time is changed, the trigger point ( ) will move horizontally, and the distance between the trigger point and the horizontal center will be indicated. The trigger point is displayed along the top of the display grid.

Trigger waveform

When the specified trigger conditions are satisfied, the trigger waveform will be displayed, and the triggering time point is called trigger point. The trigger point is general ly di spl ay ed in t he l ef t of the display screen. Foll owi ng t he tr i gger poi nt , the waveform is displayed on the display screen from left to right over time. Before using the trigger function, the user needs to configure the following parameters:

 Trigger mode

The trigger mode refers to conditions for updating the contents displayed on the screen. Including the Auto model and Normal mode Auto mode: the displayed waveform is updated in case of triggering in the pause time and automatically updated in case of no triggering in the pause tim e. Normal mode: the displayed content is updated in case of triggering and not updated in case of no triggering.

 Trigger source

The trigger source is used for generating triggering conditions. The user can select the trigger source from the input signal of the input unit and the external clock signal.

 Trigger slope

The slope refers to signal changes from low level to high level (rising edge) or from high level to low level (descending edge). When used as a triggering condition, the slope is called trigger slope.

 Trigger level

Level of trigger slope: triggering occurs when the level of the signal of the trigger source reaches the set trigger level under t he specified trigger slope conditions. When the “KNOB SEL” soft key is pressed and “ TL” is selected, the trigger level can be adjusted by rotating the knob. In this case, the trigger level can be changed by rotating the knob, and changes in the

Waveform Display Function

trigger level can be observed on the screen.

4.2 Adjustment of Measurement Parameters

You can rotate the knob to adjust the vertica l calibration, horizontal calibration, trigger delay and trigger level of the waveform display interface. Detailed steps are as follows:

Operation steps

1. Press “ ” to enter the w aveform display interface.

2. In the waveform dis play interface Press the soft key corresponding to the “KNOB SEL” parameter and select the parameter to be adjusted. When “KNOB SEL” is pressed once, the parameter to be adjusted via the knob will be switched in sequ ence among U/I/TL/TD/Td.

3. When the parameter is adjusted by rotating the knob, the interface will display changes of the corresponding value.

4.3 Setting of Trigger Configuration

When you need to enable the trigger function, you should select the trigger source, trigger mode, trigger slope and other trigger-related configuration. Detailed steps are as follows:

Operation steps

1. Press “ ” to enter the w aveform display interface.

2. In the waveform dis play interface Press the soft key corresponding to the “TIRG SET” parameter to enter the trigger setting interface, as shown below.

3. Press the right soft key corresponding to the parameter to select the required trigger configuration.

 Source: trigger source  Mode: trigger mode  Slope: trigger slope

Waveform Display Function

External trigger input (Ext)

When the trigger source is set as Ext, input the trigger signal into the external signal input interface (Synchr onous) of the rear panel according to the following specifications.

Projects

Specification

Interface t ype

BNC inter face

Input level

TTL

Minimum pulse width

1µs

Trigger delay time

Within (1μs + 3 sampling cycles)

NOTE

When the voltage higher than 0-3.3V is applied on the external signal input interface (Synchronous), the instrument may be damaged.

Minimum pulse width: refers to the width of the high or low trigger level, at least 1µs. Trigger delay time: refers to the delay between the appearance of the trigger level and the

response of CPU, within (1μs + 3 sampling cycles).

Integral Operation Function

Chapter5 Integral Operation Function

This chapter describes the features and use of the integral function of the IT9121 power meter in details.

5.1 Basic Concepts

The IT9121 power meter can be used for integral operation of the current and power of the input un it. Technical indic ators can be calculated. In addition, the range can be swi tched auto mati cally in the Buy and Sell modes accor ding t o the input level so as to accurately compl et e integr ate mea sur e ment .

During operation of the air-conditioner, refrigerator, induction cook and other household appliances, the working status will change frequently, resulting in changes of the working current in a large scale. The current m ay decrease of dozens of amperes to a few milliamperes. Ordinary power measuring instruments can only be used for integral measurement within one range. If the measured value exceeds the current maximum range, the measurem ent result is inaccurate. You need to manually switch the range before integral measurement. Integral measurement of equipment subject to large current changes cannot be performed continuously. The IT9120 series power meter can automatically switch the range in the integral mode. Therefore, errors of integral measurement caused by manual range switching can be elim inated, and the power consumption of household appliances can be measured more accurately. See the schematic diagram below.

Introduction of soft keys on the interface

When the “Integ” button is pressed, the initial integral measurement interface below will appear.

Integral Operation Function

Description of information of integral measurement interface:

Parameter name

Parameter descriptions

U_RANGE

Vol t age r ang e set ting: press the soft key c orr esp ondi ng to this paramet er to set the voltage range.

I_RANGE

Current rang e s ett i ng: press t he soft key cor r esponding to this par ameter to set the current range.

RUN/HOLD

Run/hold: press the soft key corresponding to this parameter to run or hold the integral function.

RESET

Reset.

FUNC(WP/q/AV)

Selection of the integral function: active power integral

(WP

), current integral (q) and average active power

integral (AV).

LARGE(WP/WP+/WP

-, q/q+/q-, WPAV)

Selection of the item to be displayed in a amplified manner: WP (watt hour, the sum of positive and minus watt hours), WP+ (the consumption of positive watt

hours), WP-

(the negative watt hours of feedback

power), q (ampere hour, the sum of positive and

gative ampere hours), q+ (the consumption of

positive ampere hours), q- (the negative ampere hours

of feedback power) and WPAV (average active powerintegral).

START

Integral Star t key In t he manu al st art mode, the integral

function can be enabled by press

ing the soft key

corresponding to this parameter.

STOP

Integral Stop key In the manual stop mode, the integral function can be disabled by pressing the soft key corresponding to this parameter.

SETUP

Set relevant parameters of integral measurement.

Integral Operation Function

Integral measurement display information

Description of measurement information:

Character

Function description

Mode

Display the integral start and stop mode. Start mode: MANUAL

and TIME

Stop mode: MANUAL, T I M E and TIN Terval.

State

Display the current status of the integral function.

Start: di splayed when the integral function is working.

Stop: displayed when the integral function is interrupted,

canceled or stopped. Ready: displayed in the ready state of the real-time start mode. Time Up: displayed wh

en it reaches the specified time of the

integral timer.

Reset: displayed when the integral value and integral time are

reset via integral resetting.

Error: when the power supply is recovered, the integral funct ion is

stopped and the integral result before power failure is displayed.

This integral state is called Error state.

Time

Display the integral time.

Display the set integral time.

Display the set integral ending time.

Timer

Display the fixed integral time.

Integral operation

 Active pow er integral

In watt hour, displ ayed as WP ( w at t hour s, t he su m of p osi t i ve and n egat i ve w att hours), WP+ (the consumption of positive watt hours) and WP- (the negative watt hours of feedback power).

 Current integral

In q, displayed as q (ampere hours, the sum of positive and negative ampere hours), q+ (the consumption of positive ampere hours) and q- (the negative ampere hours of feedba ck power)

 Average act ive power integral

In watt, displayed as WPAV (average active power integral)

Integral Operation Function

 Integration time

Displayed as Time, in the format of hhhh:mm:ss.

Specification

 Save in case of power failure

The integral result can be kept in the memory even in case of power failure during operation of the integral function. When the power supply is recovered and the integral function is disabled, the integral result before power failure is displayed. When the power supply is recovered and the integral is rest, the integral function is enabled again.

 Display resolution

The maximum display resolution of the integral value is 99999. When the integral v alue reaches 100000, the decimal point will move automatically. For example, when 0.01mwh is added to 999.99mwh, 1.0000wh will be displayed.

 Display in case of overflow

When the integral value meets the following overflow conditions, the integral function w i ll be di sabl ed, and the integral time and integral value at t hi s poi nt wil l be kept.

 The integral time reaches the maximum value (10000 hours).  The integral values of WP, q and WPAV reach the maxi mum/mini mum

display integral values.

 Maximum/minimum display integral value

 Active pow er integral (WP): ±99999 Mwh  Current integral (q): ±99999 MAh  Average power integral (WPAV): ± 99999 Mw

 Restricted implementation

Settings of the following functions cannot be changed during integral operation.

Function

Integration status

Integral

resetting

Current

integral status

Integral

interruption

Functions r elated to settings of m easurement parameters

Wiring

Executable

Unenforceable

Measurement range

Executable

Unenforceable

Filter

Executable

Unenforceable

Averagi ng function

Executable

Unenforceable

Synchronization

Executable

Unenforceable

Data updating rate

Executable

Unenforceable

Integral function parameter setting

Integral mode

Executable

Unenforceable

Integral timer

Executable

Unenforceable

Integral operation

Integral start

Executable

Unenforceable

Executable

Integral stop

Unenforceable

Executable

Unenforceable

Integral resetting

Executable

Unenforceable

Executable

Other operati ons

Save operat ion

Executable

Hold operation

Executable

Single measurement operation

Executable

Integral Operation Function

NOTE

In addition to the above items, other settings (such as self-testing and date/time setting) or operations with influence on the integral cannot be executed; otherwise, errors may be caused.

5.2 Setting of Integral Measurement Configuration

You can set the start mode, stop mode, automatic zero setting, automatic calibration, watt-hour integration, current integration and other parameters of integral measurement. Specific steps are as fol lows:

Operation steps

1. Press “Integ” to enter the integral measurement interface.

2. Press the soft key corresponding to the “SETUP” parameter in the integral measurement interface to enter the integral parameter configuration

interface. Press the “ ” key to select the required parameter, as shown in the figure below.

Parameter descriptions: Start: set in the MANUAL mode or TIME mode via the right soft key.

 MANUAL: press the “START” soft key in the integral measurement

interf ace i n t he manual st art mode t o tr i gger the m anual start of the int egral function.

 TIME: the date on which the integral mode is started can be set in the

real-tim e start mode. Integration will be started on the set date. When the time/date combination is set in the real-time start mode, integration will not be started before the current time and date. Integration will be started when the screen is updated once at l east before the start time.

Stop: set in the MANUAL mode, TIME mode and TINTerval mode via the right soft key.

 MANUAL: press the “STOP” soft key in theintegral measurement interface

in the manual st op mode t oman ual l y stop i nt egr ati on. When the integration time reaches the maximum integration time (10,000 hours) or the integral

Integral Operation Function

value reaches the maximum/minimum display value, integration will be stopped, and the current integral time and integral value will be kept.

 TIME: The date for stop of the integral mode can be set in the real-time

stop mode. Int egrat i on w i ll be stop ped on the s et date. When i t reach es the set time or the integral value reaches the maximum/minimum display integral value, i nt egrati on w il l be st opped, and t he c urr ent integral time and integral value will be kept.

 TINTerval: the integral measurem ent tim e can be set in the set-time stop

mode. When it reaches the set ending date and time or the integral value reaches the maximum/minimum display integral value, integration will be stopped, and the current integral time and integral value will be kept.

Integral Operation Function

Auto Clear: used for enabling (ON) or disabling (OFF) the function of automatic zero clearing of the integral. On: i ntegration is restarted when the ST A RT key is pressed to start integration. OFF: integration is restarted based on the integral value at the end of previous integration when the START key is pressed to start integration.

Auto Cal: used for enabling (ON) or disabling (OFF) the function of automatic integral calibration. W hen automatic integral calibration is enabled, zero setting is implemented. In this case, the power and current measured just now are subject to integration.

WP type: used for selecting the integral mode for positiv e and negative watt hours. There are four integral mod es:

 Charge/Discharge: used for measuring the DC positive and negative watt

hours (integration of sampling data).

 Sold/Bought: used for measuring the AC positive and negative watt hours

(value integration in each data updating cycle).

q type: used for selecting the current integration mode. Options of the current integration mode are as f ollows:

 rms: Effective value;  mn: Calibration to t he average rectified value of the effective value.  dc: Simple averaging;  rmn: Average rectified value;  ac: AC component

5.3 Integration

When the integral measurement function is enabled, you can keep the current integral information and carry out the following operations: exit, start and stop. Specific steps are as follows:

Operation steps

1. Press “Integ” to enter the integral display interface.

2. In the integral measurement display interface Press the soft key corresponding to the “START” parameter to start or recover integral operation. T he Star t st at us and integral operati on val ue ar e di splayed in the

Integral Operation Function

interface.

3. W hen you need to keep the current integral status and integral result, you can press the soft key corresponding to the “RUN HOLD” parameter. Then the current status of the integral result display and communication output will be kept no matter whether integral operation is running.

4. When you need to continue to implement integral operation, double-press

the soft key correspon ding to the “RUN HOLD” parameter to exit the HOLD status. The power meter will display the integral result after exiting the HOLD status. The schematic diagram of display of the HOLD/RUN integral result i s shown below.

5. When you need to suspend integral operation, press the soft key corresponding to the “Stop” parameter to suspend integral operation.

6. Press the soft key corresponding to the “RESET” parameter to reset the integral value and integral time. The relationship diagram of start, suspension and resetting of the integral operation status is shown below.

 Auto Clear: when ON is selected.

 Auto Clear: when OFF is selected.

Integral Operation Function

Harmonic Measurement Function

Chapter6 Harmonic Measurement Funct ion

This chapter describes the features and use of the harmonic measurement function of the IT9121 power meter i n details.

6.1 Basic Concepts

With the 100kHZ bandwidth, the IT9121 power meter can realize harmonic measurement of high speed and wide dynamic range. The voltage, current, active power, reactive power and phase of harmonics and total harmonic distortion (THD) factor can be tested in the harmonic mode. In addition, the IT9121 power meter can be used for multiple harmonic measurements, 50-order harmonics of the fundamental frequen cy at most.

The IT9121 power meter displays harmonic parameters in the list or bar chart form so as to provide cl ear analysis of test results.

Introduction of soft keys on the interface

Select the “ ” button, and the initial harmonic measurement interface below will appear.

Description of information of harmonic measur ement interface:

Parameter name

Parameter descriptions

U_RANGE

Voltage range setting: press the soft key corresponding to this parameter to set the voltage range.

I_RANGE

Current range setting: press the soft key corresponding to this parameter to set the current range.

RUN/HOLD

RUN/HOLD: press the soft key corresponding to this parameter to run/hold the harmonic status.

RESET

Reset.

FUNC(P/I/U)

Function options (power/current /voltage)

BAR

Displayed in the bar char t form

LIST

Displayed in the list form

SETUP

Parameter setting.

Harmonic Measurement Function

Introduction of harmonic information

 Description of har m onic bar chart interf ace

When the “BAR” button is selected in the harmonic measureme nt interface, the bar chart of harmonic measurement results will be displayed. The bar chart is used for displaying the percentage of different harmonics. Harmonics can be displayed in the whole sequence, odd sequence and even sequence. The following is the whole-sequence harmonic bar char t.

Description of interface information: Total harmonic parameter: including the total harmonic distortion (THD)

factor and total harmonic content. When different measurement functions are selected, different harmonic parameters will be displayed. When the soft key corresponding to the “FUNC” parameter is pressed, different measurement functions can be selected. W/I/U can be selected as the measurement function in sequence when this key is pressed once. Parameter m eanings of different functions are as follows:

 Power (P): total harmonic distortion rate of power and total harmonic

power

 Current (I): total harmonic distortion rate of current and total harmonic

current

 Voltage (U): total harmonic distortion rate of voltage and total harmonic

voltage

Single-order harmonic parameters: displaying the frequency, harmonic content, harmonic distortion factor and phase of single-order harmonics. The user can rotate the knob to select the single-order harmonics to be displayed. The selected harmonics are displayed in red in the bar chart form.

 Description of har m onic list interface

When the “LIST ” but ton i s sel ect ed i n the har monic measurement inter face,

Harmonic Measurement Function

the list of harmonic measurement results will be displayed. This list is used for showing the voltage, current, activ e power, reactive power, phase and total harmonic distortion (THD) factor of different har m onics. Harmonic lists can be displayed in the whole sequence, odd sequence and even sequence. B elow is a whole-sequence ha rmonic list.

Harmonic content: this list is used for showing all harmonic contents of single-order harmonics, including the voltage, current and power. You can view other harmonic parameters by operating the Left/Right key to turn pages. In thi s case, the line scrol l bar and current page are shown in bright white circles. Measurement parameters are described in the following table:

Abbreviations

Instruction

Abbreviations

Instruction

U(V)

Voltage

φUI(°)

Phase difference of k-order harmonic voltage and harmonic current

I(mA)

Current

UU(°)

Phase difference of harmonic

voltage U(k) and fundamental

wave U(1)

P(W)

Active power

II(°)

Phase difference of harmonic

current I(k) and fundamental

waveI(1)

S(VA)

Apparent power

U(%r)/ U(%f)

Harmonic distortion factor of voltage

Q(var)

Reactive power

I(%r)/ I(%f)

Harmonic distortion factor of current

PF()

Power factor

P(%r)/P(%f)

Harmonic distortion factor of active power

Harmonic order list: this LIST can show the data of one-order to 50-order harmoni c si gnal s. These data c an be di splayed in the whole sequen ce, od d sequence and even sequence. The rows which are not displayed, i.e. single-order harmonic data which are not displayed, can be presented by operating the Up/Down key. In this case, the row scroll bar and current page in displayed in bright blue bar s.

Harmonic Measurement Function

6.2 Setting of Harmonic Measurement Configuration

You can set the distortion factor calculation formula, PLL source, harmonic sequence and harmonic analysis times of harmonic measurement. Specific steps are as follows:

Operation steps

1. Press “ ” to enter the harm onic measurement int erface.

2. Press the soft key corresponding to the “SETUP” parameter in the harmonic measurement display interface to enter the harmonic parameter

configuration interface. Press the “ ” key to select the required parameter, as shown in the figure below.

Parameter descriptions:

Parameters

Instruction

THD Formal

Distortion factor calculati on formula. % r: displayi ng

harmoni cs in the form of percentage to the overall current (voltage, power) amplitude of all harmonics. % f: displaying harmoni cs in the form of percentage to the fundamental

wave current (voltage, power).

PLL Source

Select the PLL (Phase Locked Loop) source: U/I/OFF. Used for determining t he fundamental wave cycle as the reference for analysis of harmonic orders.

Serial

Harmonic sequence: whole sequence/odd sequence/even sequences

Order Max

Set the harmonic analysis orders (1-50). You can specify the harmonic measurement range. These specified analysis orders are used for calculating the value of the distortion factor.

Distortion factor calculation formula:

The following two formulas can be selected for calculation of the distortion factor.

 %r: using all harmonic measurement data from the minimum harmonic

order (0) to the maximum harmonic order (within the upper limit of analysis orders) as the denominator.

 %f: using the data of fundamental wave (1-order) components as the

Harmonic Measurement Function

denominator.

The distortion factor calculation formulas and methods of different measurement functions are as fol lows:

Measurement function

Calculatio n formula and method

Harmonic distortion factor of

voltage

( )

TotalU

( ) ( )

Harmonic distortion factor of

current

( )

TotalI

( )

Harmonic distortion factor of

active power

( )

TotalP

( )

Total harmonic distortion rate

of voltage

( )

TotalU

k∑=

max

( )

max

∑

Total harmonic distortion rate

of current

( )

TotalI

k∑=

max

( )

max

k∑=

Total harmonic distortion rate

of active power

( )

TotalP

k∑=

max

( )

max

k∑=

NOTE

Tot al harmonics are calculated as follows:

( ) ( )

∑

max

02k

kUTotalU

( ) ( )

∑

max

02k

kITotalI

( ) ( )

∑

max

kPTotalP

. k indicates the harmonic order, and max indicates the upper limit of

analysis orders. max is determined by the frequency of PLL source automatically, 50 orders at most.

PLL source

In the harmonic mode, IT9121 adopts PLL to multiply the frequency of the i nput signal. The frequency multiplication output signal is used as the A/D sampling clock in the instrument so as to achieve the purpose of synchronous sampling. Therefore, the frequency of the signal of the PLL source can determine the A/D sampling clock in the instrument. However, the quality of the signal of the PLL source may affect the stabili ty and accuracy of sampling data.

 PLL source selection

The voltage or c urr ent of t he i nput uni t can be sel ect ed as the PL L source. Used for determining the fundamental wave cycle as the reference for analysis of harmoni c order s. T he fundamental wave f r equency of th e P LL source is 10Hz to

1.2kHz.

 Consider ations for selection of PLL source

Please select the signal with the same cycle as that of the harmonic measurement object signal. In order to stably measure harmonics, select the input signal with little distortion as the PLL source. If the fundamental wave frequency of the PLL source changes or the fundamental wave frequency cannot be measured as a result of waveform distortion, accurate measurement results may not be obtained. When the test object i s a switch t ype pow er suppl y

Harmonic Measurement Function

and the voltage signal is subject to less distortion than the current signal, it is recommended to use the voltage as the PLL source.

 Signal level of PLL source

If the amplitude level of the signal input into the unit as the PLL source is small relative to the range, synchronization with PLL will fail. If the crest factor is set as 3, the amplitude lev el of the PLL source should exceed 50% of the range at least during setting of the range. If the cres t factor is set as 6, the amplitude level of t he PLL so ur ce sh ould exceed 100 % of the ran ge at least during setti ng of the range.

NOTE

When the fundamental wave frequency is no more than 200Hz, the frequency filter must be turned on.

When the fundamental wave frequency is lower than 440Hz and contains high-frequency components, it is recommended to turn on the frequency filter. This filter only applies to the frequency measurement circuit.

If the frequency of the PLL source changes, the correct measured value will be displayed after data are updated several times. The frequency of the PLL source needs to be tested again via the PLL circuit in the instrument in case of changes of the PLL source or its frequency, the correct measured value cannot be obtained at once.

Harmonic analysis order

The harmonic analysis order k is an integer number ranging from 0 to the upper limit of analysis orders. Zero indicates the DC c omponent. The upper limit of analysis orders is automatically determined by the frequ ency of the PLL source. The upper limit of harmonic analysis orders can be determined automatically or set manually. Take the smaller value. 50 orders at most The relationship between the upper lim it of harmonic analysis orders and the fundamental wave frequency of the PLL source is shown in the table below.

Fundamental wave frequency of PLL source

Sampling rate

Window widt h

Upper limit of

analysis orders *

10Hz ~ 75Hz

f*1024

75 Hz ~ 150 Hz

f*512

150 Hz ~ 300 Hz

f*256

300 Hz ~ 600 Hz

f*128

600 Hz ~ 1200 Hz

f*64

* The upper l imit of analysis order s can be reduced.

NOTE

If the analysis window determined by the fundamental wave frequency of the PLL source is longer than the data updating cycle, no harmonic data will be detected. In this case, the data updating cycle should be reduced. For example, when the fundamental wave frequency of the PLL source is 10Hz (cycle: 100ms), the analys i s window is one-wave long, and the data measurement interval is 100ms. In this case, the harmonic measurement time is approximately more than or equal to 150ms (data measurement interval and data processing time). Therefore, please select the data updating rate of 250ms or more for measurement and display of harmonic data.

Routine Maintenance

Chapter7 Routine Maintenance

This chapter describes general maintenance items and maintenance methods of the IT9121 power meter.

7.1 Self-inspection

The IT9121 power meter has a self-inspection function. See “Power-on Self-Test” of Chapter 3 “Inspecting the Instrument” of IT9121 Installation Instructions for detailed steps of self-inspection.

7.2 Error Information References

The IT9121 power meter has a detailed error and prompt information function, so as to help the user to easily carry out positioning and m easurement during measurement and use.

This section describes all error information of the IT9121 power meter as well as error causes and disposals. All prompt inf ormation is listed.

Prompt Message List

Prompt information

Explanation of prompt information

Cal Zero is working!

The instrument is calibrating the zero point .

Cal Zero is completed!

The instrument has completed zero point

calibration.

Test screen

Self-inspection of LC D screen

Test dsp

Self-inspection of D SP.

Test beep

Self-inspection of the buzzer.

SelfTest is finished!

The instrument has fi nished the self-test.

Softkey is not available

The current soft key is not available.

Ti me set ok!

The time setting is completed.

Meter Initialization

Initi ali zation of general measurem ent

Integ Ini tialization

Initialization of integral function

Scope Initialization

Initi ali zation of the oscilloscop e function

Harmonic Initialization

Initi ali zation of the harmonic funct ion

Inrush Ini tialization

Initi ali zation of the inrush function

Setup Initialization

Initi ali zation of setup

System Initialization

Initi ali zation of the system

Initialization is finished!

Initi ali zation is finished.

Integ start

Integration is started.

Integ stop

Integration is stopped.

Integ ti me up

The integral time is up.

Max page has been reached.

It displays The maximum page has been reached.

One page should exist at least

One page should exist at least.

Not used in current state

The current operation is not available.

Please reset first

Please reset first.

Routine Maintenance

Error information list

Error information

Error inf ormation explanation

usb is not detected

[Error description] No USB peripheral is

found.

[Possible cause] No USB peripheral is

inserted.

[Disposal] Insert the U disc type USB peripheral and then copy the screen.

Save screen fail

[Error description] The screen is not saved

successfully. [Possible cause] USB is disconnected.

[Disposal] Reinsert the USB peripheral.

Start ti me is less than cur rent

[Error description] The start time is less than

the current t ime.

[Possible cause] The integral setting is

incorrect.

[Disposal] Reset the integral start time.

End time is less than current

[Error description] The ending time is less

than the current time.

[Possible cause] The integral setting is

incorrect.

[Disposal] Reset the integral ending time.

Ti mer must b e larger than zero.

[Error description] The set time must be

larger than zero.

[Possible cause] The set integral time is not

correct.

[Disposal] Reset the set integral time.

Harmonic op en fail

[Error description] The harmonic function

cannot be enabled.

[Possible cause] Communication

abnormality

[Disposal] Check the communication cable.

Integ open fail

[Error description] The integral function

cannot be enabled.

[Possible cause] Communication

abnormality

[Disposal] Check the communication cable.

Integ start fail

[Error description] The integral function

cannot be started.

[Possible cause] Communication

abnormality

[Disposal] Check the communication cable.

Integ stop fail

[Error description] The integral function

cannot be stopped.

[Possible cause] Communication

abnormality

[Disposal] Check the communication cable.

Scope openfail

[Error description] The oscilloscope function

cannot be enabled.

[Possible cause] Communication

abnormality

[Disposal] Check the communication cable.

Ti me set fail

[Error descr iption] Time setting f ails.

[Possible cause] Tim e setting is illegal.

[Disposal] Reset the system time.

Routine Maintenance

Cal zero fail

[Error descr iption] Zero cali bration fails. [Possible cause] Communication

abnormality

[Disposal] Check the communication cable.

7.3 Daily maintenance

Introduce basic maintenance in daily use of equipment. Such as cleaning, self-maintenance allowed to be performed by the user, etc.

Equipment cleaning

Use dry cloth or slightly wet cloth to gently wipe the equipment. Do not arbitrarily wipe the inside of the instrument. Cut off the power supply before cleaning.

Initialize

When this operation is implemented, the system settings are recovered to the factory def ault values.

1. Select “SYSTEM > INITIAL” in the “Menu” interface to enter the system initi ali zation interface. See the following figure.

2. Select the menu items to be initialized (blue symbol background) via

key. Menu items wi th characters following should be i nitialized; 

indicates t hat the items will not be initialized.

3. Press the soft key corresponding to the symbol on the right of the interface to determine whether to initialize this menu item. Or use the soft key

“ ” (for initializat ion of all menu items) or “ ” (no initialization for all menu items) in the lower part of the interface.

4. Press the “START” soft key to initia lize system settings. Press the ESC to exit.

7.4 Contact of ITECH Engineers

This section describes operations to be carried out by the user in case of failure of the inst rument.

Routine Maintenance

Preparation before contact

When the instrument fails, you should make the following preparations before returning the instrument to ITECH for repair or contacting engineers.

1. Check all the items listed in the “Self-inspection of Equipment Faults” and confirm whether there are still som e problems.

2. If there are still some problems, carefully read the contents of warranty services and warranty restrictions in the preface of the manual. Confirm that our instrument co m plies with warranty ser vice conditions.

3. If you want to send the instrument to the manufacturer for repair, refer to instructions in “7.5 Returning Your Power Meter for Service”.

Self-inspection of equipment faults

In case of failure of the instrument, self-inspect the following items. If the instrument failure can be eliminated via simple inspection, the maintenance cost and time can be sa ved. Please check the f ollowing items before contacting the engineer of ITECH.

 Check whether the power meter is powered up.  Check whether the power meter is st arted normally.  Check whether the instrument fuse is in good conditions.  Check whet her oth er c onnect or s ar e i n go od con di ti ons an d w heth er cables,

plugs and other parts are connected properly.

 Check whether the system configuration of the instrument is correct during

use.

 Check whether self-inspection of the instrument is successful and whether

the specifications and performance are wit hin the indicator ranges.

 Check whether the instrument displays error information.  Use other instruments instead of this instrument for confirmation.

Collect the SN number.

ITECH will constantly improve the product performance, availability and reliability. The service personnel of ITECH will record changes of each instrument. A ll relevant information are marked uniquely according to the serial number of eac h instrum ent. The equipment returned for repair m ust adopt the SN number as the tracking ID.

When you contact the engineer, the effective SN number of the instrument will be the effective guarantee for effective service and complete information. You can obtain the SN number of the instrument by the following ways:

1. Press the Menu key to enter the system setti ng page of the power meter.

2. Press the SYSTEM to enter “SYS TEM INFO” interface to view the product model, product SN, software version number and other inf ormation.

Technical Specifications

Chapter8 Technical Specificat i ons

8.1 General Specification

Model

IT9121

AC input voltage

100VAC－240VAC 50/60HZ

Warm-up time

Apporx 30 mi nutes

Operating Environme nt

Temperature:5°C-40°C

Humidi ty: 20%-80% (non-condensation)

Altitude: ≤2,000m

Storage En vironment

Temperature: -20°C -50°C

humidi ty 20%-80% (non-condensation)

Altitude: ≤2,000m

Installation

Indoors

Safety

IEC 61010－1、EN 61010－1 、Measurement CAT Ⅱ

Polluti on degree

Polluti on degree 2

EMC

IEC 61326

Maximum power consumption 50VA

Battery backup

Backup the setting parameters

Dimension

214.5mmW×88.2mmH×354.6mmD

8.2 Screen Display

Item Detailed Information

Display Interface

Specification

Dimension 4.3-inch color liquid crystal display (TFT ) Full screen pixel 480(horizontal) × 272(vertical) points

Waveform display pixel

384(horizontal) × 194(vertical) points

Operating temperature

-20℃~ 70℃

Storage temperature

-30℃~ 80℃

Value display

Currently set up as a matrix display.It is optional to display the array number.

8.3 Input Parameters

Input parameter

Description

Input

terminals

type

Volta ge

plug-in terminal(safety terminal)

Input type

Curr ent

Direct input large binding post

External current sensor

DB9 connector

Technical Specifications

Input parameter

Description

input

Input type

Volta ge

Floating input through resistive voltage divider

Curr ent

Floating input through shunt

Measure range

Volta ge

CF=3:15V, 30V, 60V, 150V, 300V, 600V. CF=6:7.5V, 15V, 30V, 75V, 150, 300V.

Curr ent

Direct input

CF=3:5mA,10mA,20mA,50mA,100mA,200mA,0.5A,1A,

2A,5A,10A,20A.

CF=6:2.5mA,5mA,10mA,25mA,50mA,100mA,250mA,0. 5A,1A,2.5A,5A,10A.

Sensor input

EX1,

CF=3:2.5V, 5V, 10V. CF=6:1.25V, 2.5V, 5V. EX2, CF=3:50mV, 100mV, 200mV, 500mV, 1V, 2V.

CF=6:25mV, 50mV, 100mV, 250mV, 500mV, 1V .

Input impedance

Volta ge

Input resistanceApprox.2MΩ,input capacitace: Approx.13 pF(in parallel with the resistance)

Curr ent

Direct input

range5mA~2

00mA

Input resistance: Approx.505mΩ Input resistance: Approx.505mΩ

Direct input range0.5A~20 A

Input resistance: Approx 5mΩ Input inductance: Approx0.1μH

Sensor input

Input resistance: Approx 100kΩ（2.5V~10V） Input resistance: Approx 20kΩ（50mV~2V）

Continuous

maximum allowable input

Volta ge

peak value of 1.5kV or RMS value of 1kV, whichever is less

Curr ent

Direct input

range

5mA~200mA

peak value of 30A or RMS value of 20A,whichever is

less

Direct input

range

0.5A~20A

peak value of 100A or RMS value of30A,whichever is

less

Sensor input

Peak value less than or equal to 5 times of the rated range

Instantane ous maximum allowable input(1s)

Volta ge

peak value of 2kV or RMS value of 1.5kV,whichever is less

Curr ent

Direct input

range

5mA~200mA

peak value of 30A or RMS value of 20A,whichever is

less

Direct input

range

0.5A~20A

peak value of 150A or RMS value of 40A,whichever is

less

Sensor input

Peak value less than or equal to 10 times of the rated range

Input bandwidth

DC,0.5Hz~100KHz

Continuous

maximum

Common-

600Vrms,CAT Ⅱ

Technical Specifications

Input parameter

Description

mode voltage

Line fil ter select OFF, cutoff frequency of 500Hz

Frequency filter

select OFF, cutoff frequency of 500Hz

Digital filter

select OFF, cutoff frequency of 5KHz and 10KHz (this item has not been set up yet)

Range range of each unit can be set separately A/D

converter

Simultaneous conversion voltage an current i nputs

Resolution:18-bit

Maximum conversion rate: 10μs

8.4 Voltage and Current Accuracy

Item Specification

Requirements

temperature 23±5° C, hundity: 30 ~ 75%RH. Input wa veform

Sine wave crest factor:3, common-mode voltage: 0V

Number of displayed digits

5digits (6 digits when including the decimal point)

Frequency filter

Tur n on to measure voltage or cur rent of 200Hz

30 minutes after warm-up time has pas sed After zero-level compensation or measurement range

is changed

Accuracy

(The following accuracy is the sum of the re adi ng er r or

and the rang e error)

* f is the frequency of input signal in the reading error

formula, the unit is kHz.

DC ±(0.1% of reading+0.2% of range)

0.5Hz≤f<45Hz ±(0.1% of reading+0.2% of range) 45Hz≤f≤ 66Hz ±(0.1% of reading+0.2% of range) 66Hz<f≤ 1kHz ±(0.1% of reading+0.2% of range) 1kHz<f≤10kHz ±(0.07*f)% of reading+0.3% of range)

10kHz<f≤100kHz

±(0.5% of reading+0.5% of

range)±[{0.04×(f-10)}%

of reading]

8.5 Active Power Accuracy

Item Specification Requirements same as the conditions for voltage and current . Power factor:1

Accuracy(The following accuracy is the sum of the reading error and the

range error) * f

is the frequency of input signal in the reading error formula, the unit is kHz.

DC ±(0.1% of readi ng+0.2% of range)

0.5Hz≤ f<45Hz ±(0.3% of reading+0.2% of range) 45Hz≤f ≤ 66Hz ±(0.1% of reading+0.1% of range) 66Hz<f ≤ 1kHz ±(0.2% of reading+0.2% of range) 1kHz<f≤10kHz

±(0.1% of reading+0.3% of

Technical Specifications

Item Specification

range)±[{0.067×(f-1)}% of reading]

10kHz<f≤100kHz

±(0.5% of reading+0.5% of range)±[{0.09×(f-10)}% of reading]

Influence of power factor

when power f actor (PF)=0 (S:apparent power)

• ±0.2% of S for 45Hz≤f≤66Hz

• ±{(0. 2+0.2×f)% of S }for up to 100kHz as reference data f is frequency of input signal in kHz when 0<PF<1(Φ:phase angle of the Voltage and current) (power reading )×[(power readi ng error%)+(power range % )× (power range/indicated apparent power value)+{tanΦ×

(influenc e when PF=o)%}]

When the line filter is

turned ON

45~66Hz:Add 0.3% of reading

<45Hz:Add 1% of reading

Temperature coefficient same as the temperatur e coefficient for voltage and current

Accuracy w hen the crest factor is set to 6

accuracy obtained by doubling the m easurement range error for the accuracy when the crest factor is set to 3

Accuracy of apparent power S

voltage accuracy +current accuracy

Accuracy of reactive power Q

accuracy of apparent power +(√1.0004-PF2)-(√1-PF2) ×100%

Accuracy of power Factor

±[(PF–PF/1.0002)+|cosØ-cos{Ø+sin-1(influence from the power

factor when PF=0%/100)

±1digit when voltage and current are at the measurement range rated input.

Accuracy of phase

difference Φ

±[|Ø-cos-1(PF/1.0002)|+sin-1{(influence from the power factor

when PF=0%/100)

±1digit when voltage and current are at the measurement range rated input.

8.6 Voltage Current and Power measurements

Item Specification

Measurement method

digital sam pling method

Crest factor 3 or 6 Wiring system (one element model ) :single-phase ,two-wire(1P2W) Range sel ect select manu al or auto ranging

Auto range

Range incr ease

When meet any of the following conditions, the range will increase automatically.

• Urms or Irms is greater than 110% of the current setting range

• CF=3: the values of the input signal Upk and Ipk are great er than 330% of the current setting range

• CF=6: the values of the input signal Upk and Ipk are great er than 660% of the current setting range Range decrease When meet

any of the following conditions, the range will

decrease automatically.

• Urms or Irms is less than or equal to 30% of the current setting range

Technical Specifications

Item Specification

• PF=3: the values of the input signal Upk and Ipk are less than

300% of the current setting range

• PF=6: the values of the input signal Upk and Ipk are less than

600% of the current setting range

Name

Symbols and meani ngs

Measurement parameters

voltage current

Select RMS(the true RMS value of voltage

andcurrent) 、MEAN:(the rectified mean value calibrated to

theRMS value of the

voltage andthe true RMS value of the

current )、

RMN (rectified mean value of

voltage and current

DC:(simple average of voltage and

current)、 AC: alternating current、PP: (peak value

of voltage and peak value of current )

active power [W]

reactive power [var]

apparent pow er [VA]

power factor

phase difference (°)

frequency(Hz)

fU (FreqU): voltage frequency、 fI

(FreqI):

current fr equency

max/mix of voltage

(V)

Upk+: volt age positive peak、 Upk-

: voltage

negative peak

max/mix of current

(A)

Ipk+: current positive peak、Ipk-

: current

negative peak

crest factor (The ratio of peak value and RMS)

Ucf: crest fa ctor of voltage, Icf : c rest factor

of current

integration

TM:integration time 、

WP:sum of positive

and negative watt hour 、

WP+:positive power

sum 、 WP-:negat ive power sum、q:sum of positive and negative ampere-hour 、

q+:positive

ampere

-hour sum、q-:negative ampere-hour sum

Measurement

synchronization

source

Select voltage, current, or the entire period of the data updata interval for the signal used to achieve synchronization during measurement.

Line fil ter Select OFF or O N (cutoff frequency at 500Hz) Peak

measurement

Measures the peak (max,min) value of voltage,current or power

from the instantaneous current or instantaneous power that is sampled.

Technical Specifications

8.7 Frequency Measurement

Item Specification Measurement item

voltage or cur rent frequencies applied to one selected input element can be mea sured

Frequency

measurement

range

vaties depending on the data update interval (see description given later)as follows

Data update interval measurement range

0.1s 25Hz ≤ f ≤100kHz

0.25s 10Hz ≤ f ≤ 100kHz

0.5s 5Hz ≤ f ≤ 100kHz 1s 2.5Hz ≤ f ≤ 100kHz 2s 1.5Hz ≤ f ≤ 50kHz 5s 0.5Hz ≤ f ≤ 20kHz

Frequency filter select OFF or ON (cut off frequency of 500H z)

Accuracy

requirements : When the input signal level is 30% or

moreof the me asurement range if the crest factor is set to 3 (60% or more if the crest factor is set to 6) , frequency

filter is ON when measuring voltage or current of 200Hz or less. Accura cy:±( 0.06%of reading)

8.8 Harmonic Measurement

Measured i tem all inst alled elements Method PLL synchronization meth od

Frequency range

fundament al frequency of the PLL source is in the range of 10Hz to 1.2kHz

PLL source

select voltage of current of each i nput element

When PF=3, the input level is equal to or greater t han 50% of the rated range When PF=6, the input level is equal to or greater than 100% of the rated r ange When fundam ental frequency is less than or equal to 200Hz,

the frequency filter must be opened.

FFT data length 1024

Measurement parameter

Name

Symbols and meani ngs

Voltage(V)

U(k): voltage effective value of Kth harmonic

U(Total): voltage effecti ve val ue

Current(A)

I(k): curent effective value of Kth harmo nic

I(Total): curent effective value

Active power(W)

P(k): active power of Kth harmonic

P(Total): Acti ve power

Apparent

power(VA)

S(k): apparent power of Kth harmonic

S(Total): total apparent power

Reactive power(var)

Q(k): react i ve pow er of Kt h harmonic

Q(Total): total reactive power

Power factor

PF(k) : power factor of Kth harmonic

PF(Total): Total power factor

phase

φ(k): phase difference

φ: total phase

Technical Specifications

difference

(°)

between volt age and

current of Kt h harmonic\

φU(k): voltage phase

difference Kth harmonic(UK) and

fundamental wave(U1) φI(k): phase difference current phase difference between Kth

harmonic(IK)

and fundament al wave(I1)

difference

harmonic distortion factor (%)

Uhdf(k): Voltage ratio of Kth harmonic(Uk) and fundmental wave(U1) or total distortion

wave(Utotal) Ihdf(k): current ratio of Kth harmonic（ Ik）

and

fundmental wave(I1）

or total di storti on wave(I total ) Phdf(k): active power ratio of Kth harmonic(Pk)and fundmental wave or total distortion wave(Ptotal)

(THD)total harmonic distortion (%)

Uthd: voltage ratio of total harmonic and

fundmental

wave(U1) or total distortion

wave(Utotal)

Ithd: curr ent ratio of total harmonic and fundmental

wave(I1) or total distortion wave(Itotal)

Pthd: active power ratio of total harmonic and fundmental wave(P1) or total distortion wave(Ptotal)

Window function

Rectangle

Note: K is a integer from 0 to upper limit of harmonic analyse times.0th means DC parameter. User can configure the maximum number of harmonic times manually or auto-decided by equipment, taking the minmum value between the two methods. IT9121 can measure up to 50th harmonic..

8.9 Fundamental Frequency

Fundamental frequency

sample rate window width

upper limit of* analysis orders*

10Hz ~ 75Hz f*1024 1 50 75Hz ~ 150Hz f*512 2 32 150Hz ~ 300Hz f*256 4 16 300Hz ~ 600Hz f*128 8 8 600Hz ~ 1200Hz f*64 16 4 *the upper limit of analysis orders can be decrease

8.10 Accuracy

*When line filter is off, the accuracy shown below is the sum of reading and range errors.

Frequency

Voltage

Current

Power

10Hz≤f<45Hz

0.15% of reading +0.35% of range

0.15% of reading +0.50% of range

Technical Specifications

45Hz ≤ f ≤

440Hz

0.15% of reading

+0.35% of range

0.15% of reading

+0.35% of range

0.20% of reading

+0.50% of range

440Hz<f ≤

1kHz

0.20% of reading

+0.35% of range

0.20% of reading

+0.35% of range

0.40% of reading

+0.50% of range

1kHz<f ≤

2.5kHz

0.80% of reading

+0.45% of range

0.80% of reading

+0.45% of range

1.56% of reading

+0.60% of range

2.5kHz<f ≤

5kHz

3.05% of reading

+0.45% of range

3.05% of reading

+0.45% of range

5.77% of reading

+0.60% of range

8.11 Oscilloscope Function

Channel

Measurement V ol tage and curr ent Bandwidth(-3dB) DC : 10 kHz Sample rat e 100kHz Record length Each channel is 300 poi nts

Horizontal system

The level of s cale

range

500us/case, 1ms/case, 2ms/case, 5ms/case, 10ms/case, 20ms/case,

50ms/case, 100ms/case, 200ms/case, 500ms/case

The accuracy of horizontal cursor

Each case i s ±4.0%

Vertical system

Vertical scale range

CF=3: Range/case CF=6:Range*2/case

The accuracy of the vertical cursor

Each case i s ±4.0%

Maximum input voltage

1800V (DC+AC peak)

Maximum input current

60A (DC+AC peak)

Triggle system Trigger source Voltage, current and EXT Trigger type Edge(ri sing edge, falling edge, arbitrary edge) Trigger mode Automatic, Normal, Single

8.12 Interface Specification

USB Interface

Item

Specification

Interface t ype

Type B (socket)

Electrical and mechanical specifications

USB 2.0

Tr ansmission speed

Maximum speed is 12Mbps

Port number

Power supply

Self-powered

Support service

Remote control

Support system

Run PC with Windows 7(SP4 version or

Technical Specifications

update version), Windows XP or Windows Vista,standard USB interface.

USB peripheral equipment interface

Item

Specification

Interface t ype

T ype A (socket)

Electrical and mechanical specifications

USB 2.0

Tr ansmission speed

Maximum speed is 12Mbps

Port number

Power supply

Power supply 5V、500mA2 (per port)

Support USB large capacity memory

USB flash memory ( meet USB Mass Storag e

Class Specification)

Support system

Run PC with Windows 7(SP4 version or

update version),

Windows XP or Windows

Vista,standard USB interface.

GP-IB Interface

Item

Specification

Available equipment

America NI Company

• AT-GPIB

• PCI-GPIB or PCI-GPIB+

• PCMCIA-GPIB, PCMCIA-GPIB+ or PCIe-GPIB Drive program: NI-

488.2M 1.60 or update

version

Electrical and mechanical specifications

IEEE St’d 488-1978 (JIS C 1901-1987)

Functional specification

SH1, AH1, T6, L4, SR1, RL1, PP0, DC1, DT1, C0

Protocol

IEEE St’d 488.2-1992

Encoding

ISO (ASCII)

Mode

The address mode can be set

Serial port(RS-232)

Item

Specification

Electrical Specification

Comply with EIA-232(RS-232) standard

Connection type

Point to point

Communication type

Full duplex

Synchronization

Start and stop can be synchronized

Baud rate

The baud rat e can be set(Default:9600)

Start bit

1 bit

Data length

8 bits

Parity bit

NONE

Stop bit

1 bit

Ethernet Communication

Item

Specification

Port number

Interface

RJ-45

Electrical and mechanical specifications

IEEE802.3

Technical Specifications

Transmission system

Ethernet (100BASE-TX)

Tr ansmission speed

Maximum speed: 100Mbps

Communication protocol

TCP/IP

Support equipment

FTP service、DHCP、DNS、Remote control

(VXI-11)

Thanks for purchasing ITECH products. In case of any doubts, please contact us as follows:

Refer to accompanying data disk and relevant manual.

Visit ITECH website:www.itechate.com

Select the most convenient contact method, for further information.

ITech IT9121 Series User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual