We specialize in Current Sensors, CT Sensors, and Measuring Instruments.

AC Leakage Clamp Meter

HWT-301 Digital Harmonics Clamp Tester40mmφCT, ACA harmonics up to 25th, ACV, Ω

AC Leakage Current, 400mA/4A/40A/300A
True rms reading, 40mmφCT
Harmonics Current and Voltage


Harmonics and leakage current measurements.
Up to 25th harmonics current and voltage measurements.
True rms reading for ACA and ACV.
Data-hold and Auto power off function.
Conform to IEC safety requirements.

What are harmonics ? Let's try to measure by HWT 301

Operating Temperature 0℃ to 40℃, 80%RH max. ( Without condensation )
Power supply 1.5V (AM-4, LR03 or AAA)×3
Power consumption 13mA
Weight Approx. 440g
AC Conversion True rms responding
Safety standard IEC 61010-1, IEC 61010-2-032, Installation
CategoryⅡ600V or CategoryⅢ300V
Jaw opening capability 40mmφ
Size 70(W)×223(H)×34(D)mm
Accessories Hard carrying case
Instruction manual
Crest factor < 3 (0~50% of range)
< 2 (50~100% of range)
Display 3.5 digit LCD, max. reading of 3999
Over range indication "OL" mark on LCD
Data hold indication "DH" mark on LCD
Low battery indication "Battery" mark on LCD
Auto power off Approx.20 minutes later after power on
E.M.C. standard EN 61326
Measuring method Dual slope integration mode
Battery life Approx.50 hours continuous
Sampling 2 times/sec
Affection of magnetic field 3mA or less (at 100A nearby conductor)
Input Frequency 45Hz~65Hz
Withstanding Voltage AC 3700V 1 minute max. (Between the core of CT and outer case)
Storage Temperature 10℃ to 60℃, 70%RH max. ( Without condensation )
Accuracy (23℃±5℃, 80%RH or less)
AC 400mA/0.1mA/±1.0% rdg ± 8 dgt/AC 300Arms
AC 4A/1mA/±1.0% rdg ± 8 dgt/AC 300Arms
AC 40A/10mA/±1.0% rdg ± 8 dgt/AC 300Arms
AC 300A/100mA/±1.0% rdg±1% of full scale/AC 300Arms
AC 400mV/0.1mV/±1.0% rdg ± 8 dgt/AC 250Vrms
AC 400V/100mV/±1.0% rdg ± 8 dgt/AC 450Vrms
4000Ω/1Ω/±1.0% rdg ± 8 dgt/AC 400Vrms
Harmonics mode
Measuring method Synchronous filter
Measurable harmonics Fundamental to 25th harmonics
Minimum input More than 5% of full scale in each range
Accuracy Harmonics/Accuracy(In case of more than 4% harmonics is included against fundamental input)
1~9th/(±1%rdg±5 dgt)±(basic accuracy of ACA or ACV)-(Error by neighboring harmonics)
10~19th/(±2%rdg±5 dgt)±(basic accuracy of ACA or ACV)-(Error by neighboring harmonics)
20~25th/(±5%rdg±5 dgt)±(basic accuracy of ACA or ACV)-(Error by neighboring harmonics)