GAOTek Double Clamp Digital Phase Volt-Ampere Meter

This intelligent Double Clamp digital Phase Volt-Ampere Meter is used in the direct measurement of AC voltage and current, and also used for indirect measurement of power factor and power of the circuits.




GAOTek Double Clamp Digital Phase Volt-Ampere Meter is used in the direct measurement of AC voltage and current, without opening the measured circuit, phases between three voltages, three currents and phase between the voltage and current. In addition, the power factor and power of the circuit can be indirectly measured. It can also be used to distinguish three-phase sequence, transformer wiring group, inductive and capacitive circuits, test second circuit and bus differential protection. It provides simplified operational use with high accuracy and stability and low power consumption. It reads the phase relationship between CTs of the differential protection, checks the meter wiring, repairs lines and equipment. It is composed of a well-designed shell which is highly insulated.


  • Compliant with IEC61010-1 CAT Ⅲ 600 V, IEC61010-031, IEC61326, 2 class of pollution
  • Digital intelligent meter
  • Easy to use
  • Small mouth clamp suitable for use in dense locations
  • Equipped with shake-proof and skid-proof well designed shell
  • Fully automatic and multi-functional
  • Data storage of up to 1500 sets
  • USB-RS-232 interface to download data to computer for analysis and management
  • Data upload through software
  • LCD display with backlight
  • Automatic shut-down if idle time exceeds 15 minutes

Technical Specifications

1. Base Conditions and Working Conditions

Influence Quantity Base Condition Working Condition Remark
Ambient temperature 73.4°F (23℃ ± 1℃) 14°F~104°F (-10℃~40℃) —-
Ambient humidity 40 %~60 % <80 % —-
Signal waveform Sine Wave Sine Wave β=0.01
Signal frequency 50 HZ ± 1 HZ 45 HZ~65 HZ —-
Meter working volt 9V ± 0.1V 9V ± 1.5V —-
Current amplitude in Phase/frequency/Phase sequence test 1A ± 0.2A 2mA~20A —-
Voltage amplitude in Phase / frequency/ Phase sequence test 100V ± 20V 10V~600V —-
Current amplitude in power / Power factor test 1A ± 0.2A 20mA~20A —-
Voltage amplitude in power / Power factor test 100V ± 20V 10V~600V —-
External electric magnetic field To be Avoided
Measured wire position Measured Wire at Approximately the Geometric Centre of the Clamp

2. Intrinsic Error and Performance Indicators under Base Conditions

Category Measurement Range Resolution Intrinsic Error
Voltage AC 0.0 V~600 V 0.01 V ± (1.5% rdg + 3 dgt)
Current AC 0.0 mA~20.0 A 0.1 mA ± (1.5% rdg + 3 dgt)
Phase 0.0°~360° 0.1° ±1°
Active power 0.0 W~12 kW 0.1 W ± (3% rdg + 3 dgt)
Reactive power 0.0 VAR~12 kVAR 0.1 VAR ± (3% rdg + 3 dgt)
Apparent power 0.0 VA~12 kVA 0.1 VA ± (3% rdg + 3 dgt)
Frequency 45 HZ~65 HZ 0.01 HZ ± (2% rdg + 3 dgt)
Power factor -1~+1 0.001 ±0.03

3. General Specifications

Measurement range

(Automatic shift)

AC Voltage:0.00 V~600 V (Automatic Shift)
AC Current:0.0 mA~20.0 A (Automatic Shift)
Frequency:45.00 Hz~65.00 Hz
Active Power:0.0 W~12 kW
Reactive Power:0.0 W~12 k VAR
Apparent Power:0.0 W~12 kVA
Power Factor:-1~+1
Resolution Voltage:AC 0.01 V
Current:AC 0.1 mA
Frequency:0.01 Hz
Active Power:0.1 W
Reactive Power:0.1 VAR
Apparent Power:0.1 VA
Power Factor:0.001
Power DC 9 V Alkaline Batteries(1.5 V AA × 6)
Consumption About 70 mA with Enabled Backlight, Battery Working Continuously for About 14 hours
About 40 mA with Disabled Backlight, Battery Working Continuously for About 20 hours
Clamp size Acuminate Current Clamp: 0.2 in × 0.5 in (7.5 mm × 13 mm)
Meter size 7.7 in × 3.6 in × 2.1 in (196 mm × 92 mm × 54 mm)
Current clamp length 78 in × φ 0.19 in (2 m × φ 5 mm)
Display mode LCD Display, 240 dots × 160 dots
Sampling rate About 2 times / s
Test Line length 4.9 Ft (1.5 m)
Data storage 1500 Sets
Battery voltage Indicating the battery voltage is lower than 7.2 V
Weight Main Unit: 1.2 lbs (0.55 Kg)(With Battery)

Acuminate Current Clamp: 0.3 lbs (0.17 kg × 3)

Round Current Clamp: 0.3 lbs (0.18 kg × 3)

test line: 0.55 lbs (0.250 kg)

Input impedance 2 MΩ for Testing Voltage
Withstand voltage Withstands 1000 V / 50Hz Sine Wave AC voltage for 1 Minute between the Meter Lines and Shell;Withstand 500 V / 50 Hz AC Voltage Sine Wave for 1 Minute between the Two Voltage Inputs
Temperature and humidity Working: 14 °F ~ 104 °F (-10 ℃ ~ 40 ℃), below 80 % RH

Storage: 14 °F  ~ 140 °F (-10 ℃ ~ 60 ℃), below 70 % RH

Insulation ≥100 MΩ between Meter Lines and Shell or between the Two Voltage Inputs
Structure Double insulation with Vibration-Proof Sheath

Additional Information


  • Electric power and petroleum chemical industry
  • Metallurgy
  • Railway
  • Meteorology
  • Industrial and mining enterprises
  • Scientific research institutions
  • Measurement sector
  • Electricity billing and relay protection system
  • Electricity measurement and check
  • Power inspection for power marketing department


  • Under any circumstances, please pay special attention to your safety while using this instrument
  •  Give heed to label texts and symbols on panel and back plate of this Clamp Meter
  • Make sure that the instrument and accessories are intact and there is no damage to the instrument or test wire insulation layer or bare and broken wires before using it
  • Make sure that the function switch has been set up within the appropriate range before the test
  • Cannot be used to test voltage higher than 600 V
  • It is prohibited to use the instrument without the rear cover and battery cover in place
  • Make sure that the connection plug is closely inserted in the socket
  • Don’t use or replace batteries if the instrument is wet
  • Test is prohibited in flammable and dangerous places
  • The test line can only be pulled out from the instrument after being removed from the measured wire; Don’t touch the jack plug  by hand to avoid an electric shock
  • Do not use the instrument in strong electromagnetic environment in order to prevent the equipment from working inefficiently
  • Don’t operate two or more buttons simultaneously as the operation will be invalid
  • Stop using the meter in case of metal exposure due to a broken chassis or fractured test line
  • Do not place or keep the device in hot and humid environment or places of moisture or direct sunshine for a long time
  • The instrument and current clamp must be maintained regularly to keep it clean. Corrosive solution and coarse materials can’t be used to clean the clamp
  • Keep the current clamp free from any impact, especially the clamp joints
  • The instrument has an automatic shutdown function. Remove or replace the battery if the instrument is not used for a long time and take note of the battery polarity
  • Take note of the measurement range and application environment required for the instrument
  • The operation, demolition, calibration and maintenance of the instrument must be carried out by qualified personnel authorized to do so
  • The meter should be stopped from being used immediately and sealed if danger is encountered in case of continued use; only a competent body can be authorized to deal with it
  • The two COM ports of the instrument is internally short circuited
  • Users shall carry out operation based on danger  signs on the meter
  • Users shall carry out safety operation based on instructions listed e.g. “” and danger signs on this manual


Model Clamp Size Note
GT00Y900ZZ 0.2 in × 0.5 in Acuminate Current Clamp

Electrical Signs

Extremely dangerous! Operators shall strictly observe safety rules; otherwise there would be dangers of electric shock which may cause personal injuries or casualties
Dangerous!Operators shall strictly observe safety rules; otherwise there would be dangers of electric shock which may cause personal injuries or casualties.
Warning!Operators shall strictly observe safety rules; otherwise personal injuries or equipment damages might be caused.
  Double insulation

Instrument Structure

  1. USB-RS232 interface
  2. Insulation vibration-proof sheath
  3. LCD display
  4. Function keys area
  5. Two voltage input interface
  6. Current clamp input interface I2
  7. Current clamp input interface I1
  8. Current clamp output plug
  9. Acuminate current clamp (optional)
  10. Round current clamp (optional)
  11. Voltage input test line

Method of Operation

Check carefully before using the instrument whether there are damaged parts. No damage is allowed
The instrument is prohibited from use in dangerous places.
Install the battery according to the manual
Don’t simultaneously operate two or more buttons. The operation will be invalid.

 1. Switch On/Off

Press  button to switch on as shown on the LCD or press to switch off. Boot needs 5 seconds to finish internal automatic calibration of the instrument. The device powers off automatically after 15 minutes.

2. Backlight Control

Press  to control the backlight in dim places.

  1. Date Lock / Release / Storage

In test mode, press HOLD key to Lock currently displayed value and display “HD “symbol. At the same time, these lock-values as a set of data followed by auto-ID display the group number such as“S:01”. Then press the HOLD key to cancel the lock. “HD” symbol disappears. The user can continue to measure. Loop operation can store 500 sets of data. If the memory is full, the LCD display will show “FULL” symbol.

  1. Date Access / Exit

In the test state, press the key to access date inquiry form group “R:01”, and display “RD” symbol. It is allowed to rapidly navigate to the desired page number. Press “ △ ”key to increase the page number by one. Press ”▽” key to increase the page number by ten. Press “◁”key to exit date inquiry and back to test state.

  1. Data deletion

In the data inquiry state, press “▷”key to access data deletion menu. Press the key with the cursor located at “YES” to delete the stored data. Press the key with the cursor at “NO” to cancel the deletion and return to the test state.

  1. Date Upload

Connect the meter and a computer with the USB-RS232 communication line. Start the meter, run the software, choose history access then read, save, report, print historical data, etc. The more the data the longer it takes to read it. Historical data can be saved in Txt text or Excel format.


High voltage, extremely dangerous! Operators shall strictly observe safety rules; otherwise there would be risk of electric shock which causes personal injuries or casualties
Dangerous!Cannot be used to measure voltage higher than 600 V; otherwise there would be risk of electric shock which causes personal injuries or equipment damages
Dangerous! Cannot be used to test current higher than 20 A. Otherwise it may damage the equipment.
Connect the wire strictly in accordance with the manual instructions. I1 and I2 cannot be confused
After testing, firstly move the test wire away from the measured circuit and then pull out the test wire from meter.
Phase Test relationship of the instrument: U1U2、I1I2、U1I1、U2I2, for every relationship the measured phase shows the former signal ahead of the latter signal.
P1、Q1、S1、PF1 corresponding to the parameters of U1-I1;  P2、Q2、S2、PF2 corresponding to the parameters of U2-I2.
The red U1, U2 voltage jacks and the red dot marks or arrow symbols on the clamp are dotted terminals
In phase test, the direction of the input current should be in line with the arrow symbol on the clamp

This instrument can test two AC voltage, current, phase between voltage, phase between current, phase between voltage and current, frequency, active power, reactive power, apparent power, power factor, three-phase current vector sum, distinguish phase sequence, inductive,  capacitive circuit, etc.

Test connections are as follows:

Single-phase test: Connecting the measured wire L/N corresponding to U1 red/COM black jack of the instrument. Clamp L wire by current clamp I1 to test the single line voltage, current, phase, frequency, power parameters, etc. Also the user can connect U2 red, COM, I2 to test. This is shown below:

Three-phase four-wire test: Connect the wires in two steps to test three-phase four-wire voltage, current, phase, phase sequence, frequency, power, power factor, etc as shown below (The two COM ports of the instrument is internally short circuited, connect either of them to null line N)

Step 1 Step 2
Three-phase four-wire circuit Meter Three-phase four-wire circuit Meter
UA yellow U1 red UB green U1 red
UB green U2 red UC red U2 red
N black COM black N black COM black

Three-phase three-wire test: Connect the measured wire UA yellow, UB green, UC red corresponding to U1 red, COM black, U2 red  jack of the instrument. Clamp wire IA, IC respectively by current clamp I1, I2 to test three-phase three-wire voltage, current, phase, phase sequence, frequency, power, power factor, etc as shown below (The two COM ports of the instrument is internally short circuited, connect either of them to null line N)

During test, according to various phase relationship, inductive or capacitive loads, phase sequence and polarity can be judged. If U1I1 phase display within 0°~90°range, the measured load is perceptual; if within 270°~360° range, the measured load is capacitive. If the phase display is near 120°, it is positive phase sequence and the same polarity; if near 120°or 300°, it is positive phase sequence and the opposite polarity (may be current clamp or wire reverse connection). Other conditions for negative phase sequence (except default phase).

Battery Replacement

Take note of the battery polarity. The polarity must be properly installed, otherwise it causes damage to the instruments
Battery replacement is prohibited in hazardous area
Must use qualified alkaline batteries(1.5V AA × 6)
Old and new batteries are not allowed to be used together
  1. ”is displayed when the power voltage is lower than 8 V ~ 8 V, indicating that the battery should be replaced
  2. Press to switch off
  3. Use the cross screwdriver to loosen the screw on the battery cover. Open the battery cover.
  4. Remove the old batteries and replace with the new battery. Please note the battery polarity
  5. Cover the battery cover, tighten the screws
  6. Press to switch on to check whether the instrument is working with the battery replaced. Repeat step 2 if it doesn’t work
  7. Take out the batteries if the instrument will not be used for a long time.

Other Descriptions and Notes

  1. The special utility of current clamp: The two current clamps of each meter can only be used on this instrument. The current clamp should be prevented from any impact. The clamp surface must be kept clean and should be closed completely for a reliable test
  2. The maintenance of current clamp: The dust on the surface of the current clamp should be removed promptly after use; don’t use rough material or corrosive substances to clean the clamp. It is best to gently wipe with a clean soft cloth and lubricants (for example: WD-40 lubricants)
  3. Preheat 3 to 5 minutes before the measurement to ensure the measurement accuracy
  4. The instrument should be used for secondary and low-voltage circuit detection and cannot be used to measure the current of high-voltage lines to prevent electric shock.
  5. Three-phase four-wire system (Phase of a balanced three phase load)
Phase Relationship Phase Value Phase Relationship Phase Value
Ua-Ub 120° Ia-Ib 120°
Ub-Uc 120° Ib-Ic 120°
Uc-Ua 120° Ic-Ia 120°
  1. Three-phase three-wire (Phase of a balanced three phase load):
Phase Relationship Phase Value Phase Relationship Phase Value
Uab-Ucb 300° Ia-Ic 240°
Uab-Ia 30° Ucb-Ic 330°
  1. Three-phase four-wire vectogram and Three-phase three-wire vectogram:


Main Unit 1 piece
Meter Box 1 piece
Current Clamp 3 pieces
Test Line 4 pieces(2 Yellow, 2 Black)
RS232 Data Line 1 piece
Disk 1 piece
Battery 6 pieces (Alkaline Dry Battery: 1.5 V AA)
User Manual 1 copy
Guarantee Card 1 copy
Certification 1 copy