Product Sep. 23, 2015

Hioki Launches the Phase Detector PD3129 and PD3129-10

Instruments Make Detection of Normal Phase Even More Intuitively with Illuminated Arrow Indicator

September 23, 2015 - Nagano, Japan

Hioki is pleased to announce the launch of the Phase Detector PD3129 and PD3129-10.

Hioki previously launched the 3129 as a no-metal-contact phase detector in 2004, followed by the 3129-10 with a larger voltage sensor in 2007. Up to that time, most similar instruments had metal clips that had to be affixed to measurement terminals, raising concerns about electric shocks and short-circuits. The 3129 gained a large customer base following its launch because it allowed users to avoid such hazards.

The newly launched PD3129 and PD3129-10 make it even easier to check measurement results by adding illumination to the arrow located in the middle of the instrument.

The PD3129 has voltage clips with a measurable diameter of 2.4 to 17 mm, while the PD3129-10 offers clips that have a measurable diameter of 7 to 40 mm.

What Is a Phase Detector?
A phase detector is an instrument that measures a 3-phase, 3-wire connection to ensure that the phases are connected in the proper order. Three-phase, three-wire connections use three wires to supply three AC voltages, and a phase detector is used to verify that the three AC voltages are operating in the correct order (in normal phase). Use of equipment with the three lines out of phase invites equipment damage and other issues.

Features of the PD3129 and PD3129-10
1. Illuminated arrow for intuitive detection
When the PD3129 series detect normal phase, the arrow in the middle of the instruments turn green, making it easy to verify normal phase. Since the indicator is designed so that it appears clearly when photographed, the instruments are convenient to use in photographs taken for use as visual proof in reports.

2. Easy verification of measurement results with LED and a buzzer
The PD3129 and PD3129-10’s measurement results also can be checked by means of an LED and buzzer. The LED’s flash pattern and the buzzer’s tone differ for normal and reverse phase, providing an intuitive understanding of measurement results.

3. Functionality to make site work even more convenient
The PD3129 and PD3129-10 also provide a range of functionality designed to provide even greater convenience in the field:

* Battery check function: The instruments prevent abrupt loss of battery power by notifying the user of declining battery life with a flashing “ON” lamp.
* Auto power-off: The instruments automatically turn off once they have been on for 15 minutes. This feature helps prolong battery life.
* Magnetic back: Four magnets on the back of the instruments allow them to be secured in place on distribution panels, freeing the user’s hands for other work.


Established in 1935, HIOKI E.E. CORPORATION (TSE: 6866) has grown to become a world leader in providing consistent delivery of test and measuring instruments through advanced design, manufacturing, and sales and services. By offering over 200 main products characterized by safety and quality while meeting an expansive range of applications, we aim to contribute to the efficiency and value of our customers' work in research and development, production and electrical maintenance. HIOKI products and services are available around the world through our extensive network of subsidiaries and distributors. Information about HIOKI is available at

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PD3129-10 Phase Detector