FT6031-90 - Earth Tester with Bluetooth for 2-Pole and 3-Pole Measurement

Key Specifications

• 2-pole and 3-pole earth resistance measurement 
• Bluetooth communication included
• Automatic interference voltage and auxiliary earth resistance check
• IP67 dustproof and waterproof 

Typical Applications

• Grounding system inspection in electrical installations
• Verification of existing earth electrodes during maintenance and periodic testing 
• Service and maintenance of protective earthing systems

Detailed Product Overview  

The HIOKI FT6031-90 is an earth tester for electrical professionals in service, maintenance and inspection. It provides 3-pole measurement for precise earth resistance testing and also offers a simplified 2-pole method for situations where auxiliary earth spikes cannot be used for a full test setup. The FT6031-90 bundles the FT6031-50 with the Z3210 Bluetooth Adapter, adding Bluetooth communication to the instrument. 

2-pole and 3-pole earth resistance measurement 

The FT6031-90 supports both 3-pole and 2-pole earth resistance measurement. The 3-pole method is used when the earth resistance of an existing earth electrode needs to be measured as accurately as possible. In this setup, the earth electrode under test is disconnected from the installation and measured with two auxiliary earth spikes. The required test leads and auxiliary earth spikes are already included with the FT6031-90, with 10 m and 20 m lead lengths for a typical field setup. The instrument measures at 128 Hz ±2 Hz, with an output voltage of 30 V rms or less and a test current of 25 mA rms or less. A measurement typically takes up to 6 s, including automatic checks for interference voltage and auxiliary earth resistance. 

The 2-pole method is intended for situations where a full 3-pole setup is not possible or practical. Instead of using two auxiliary earth spikes, it uses an existing low-resistance earth as a reference, typically the neutral side of a grounded power supply. The result therefore includes not only the resistance of the earth electrode under test, but the combined resistance of the test earth and the reference earth. In this mode, the test current is limited to 4 mA rms or less, which is intended to avoid tripping residual current devices under suitable installation conditions. The 2-pole method is therefore used for simplified checks rather than for the most precise measurement of a single earth electrode. 

Instrument functions and accessories 

The FT6031-90 is designed to reduce setup effort and make measurement results easier to assess in the field. Before a measurement starts, the instrument automatically checks for interference voltage on the earth electrode and verifies the resistance of the auxiliary earth spikes. Zero adjustment compensates for the resistance of the test leads, which is especially helpful when longer leads are used. A comparator function is available for direct PASS/FAIL evaluation against a defined limit, and a continuous measurement mode helps when auxiliary earth spikes need to be repositioned during setup. 

For applications with longer distances between the instrument and the measurement points, optional leads such as the L9843-51 and L9843-52 are available. On concrete or other hard surfaces where auxiliary earth spikes cannot be inserted directly, 9050 Earth Nets or L9846 Earth Nets Modules can be used. The L9846 modules can be attached to the supplied L9842-11 and L9842-22 lead reels as well as to the separately available L9845-31, L9845-33 and L9845-52 reels, forming a single assembly. 

Bluetooth Communication included 

The FT6031-90 is supplied with the Z3210 Bluetooth Adapter, adding wireless data transfer to the FT6031-50. Measured values can be transferred to Windows, iOS or Android devices. For smartphones and tablets, the free GENNECT Cross app is available for displaying, storing and documenting readings. Alternatively, the Z3210 can operate in HID mode, where measured values are sent to the active application as keyboard input. This allows direct data entry into Excel, text applications or custom software applications. 

Like all HIOKI earth testers, the FT6031-90 was developed in Japan and is manufactured at HIOKI’s own production facilities in Nagano Prefecture, Japan.