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Hioki is a leading manufacturer of electrical measuring instruments and test equipment, providing precision solutions for power analysis, battery testing and industrial maintenance. Its portfolio includes digital multimeters, clamp meters, power analysers, battery testers, data loggers and insulation testers. Trusted by engineers, electricians and researchers worldwide, Hioki products support applications in energy, automotive, electronics manufacturing and electrical maintenance.
Earth Tester Set with Selective and Stakeless Testing
Earth resistance meter for stakeless and selective earth testing, 4-pole earth resistance and soil resistivity measurement, separate 4-terminal resistance measurement, IP67 protection, Bluetooth optional.
• Earth resistance measurement: 2-pole, 3-pole and 4-pole
• FT9847 and CT9848 included for selective and stakeless earth testing
• Soil resistivity measurement with 4-pole Wenner method
• Separate 4-terminal resistance measurement
• Optional Bluetooth communication with Z3210
• Selective earth resistance measurement in connected grounding systems
• Stakeless earth resistance measurement in multiple-earthed systems
• Earth resistance measurement in electrical installations and industrial grounding systems
• Soil resistivity measurement according to Wenner for grounding design and site surveys
• Continuity and resistance measurement between earth electrodes and installations
The HIOKI FT6041-91 is an earth tester set for electrical professionals working in service, maintenance, inspection, and grounding design. It combines 2-pole, 3-pole, and 4-pole earth resistance measurement with soil resistivity measurement and separate 4-terminal resistance measurement in one instrument. With the included CT9848 Signal Detection Clamp and FT9847 Signal Induction Clamp, the set also supports selective earth resistance measurement, which HIOKI refers to as Measuring Earth with a Clamp (MEC), as well as stakeless earth resistance measurement.
Rated IP67 for dust and water protection, the FT6041-91 includes test leads on reels, auxiliary earth spikes, earth nets modules, and the FT9847 and CT9848 clamps. This means the set covers conventional earth testing with auxiliary earth spikes as well as selective and stakeless methods. Measurements on concrete and other hard surfaces can also be carried out with the accessories included in the set.
For checking the earth resistance of an existing earth electrode, the FT6041-91 provides a 3-pole method with two auxiliary earth spikes. In this setup, the earth electrode under test is disconnected from the installation for measurement. The test voltage can be switched from 30 V to 20 V in very wet conditions. If a full 3-pole setup is not possible or practical, the instrument also offers a simplified 2-pole method.
In 2-pole measurement, the selectable test voltages are 8 V and 20 V. The measurement frequency can be set to 94 Hz, 105 Hz, 111 Hz, 128 Hz, or 55 Hz to reduce the influence of noise or adapt the measurement to site conditions.
For soil resistivity surveys, the FT6041-91 supports 4-pole measurement based on the Wenner method. The instrument measures resistance and calculates soil resistivity in Ω·m from the selected electrode spacing. In this mode, the test voltage can also be switched between 30 V and 20 V. Electrode spacing can be set from 1 m to 50 m in 0.1 m steps, or from 3 ft to 160 ft in 1 ft steps.
The FT6041-91 includes the CT9848 Signal Detection Clamp and the FT9847 Signal Induction Clamp for selective and stakeless earth resistance measurement. For selective earth resistance measurement, HIOKI uses the term Measuring Earth with a Clamp (MEC). In this method, the CT9848 detects the measurement current of a specific earth electrode in a connected multiple-earthed installation, so the electrode does not need to be disconnected for the test. Depending on the application, this can be carried out as a 3-pole or 4-pole measurement with a clamp.
For stakeless earth resistance measurement, the FT9847 injects the test signal into the grounding conductor while the CT9848 senses the resulting current. This two-clamp method is intended for multiple-earthed systems and works without auxiliary earth spikes. Because both clamps are already included, the FT6041-91 covers both clamp-based methods as part of the set.
The FT6041-91 also includes dedicated 2-terminal and 4-terminal resistance measurement. This is useful, for example, when an earth electrode has been disconnected for a 3-pole test and the connection needs to be checked after it has been reconnected. The 2-terminal mode is suited to basic continuity checks, while the 4-terminal mode minimizes the influence of lead resistance and allows more accurate low-resistance measurement of earth connections. In many cases, there is no need for a separate resistance meter.
The FT6041-91 includes two L9846 Earth Nets Modules. They are used where earth spikes cannot be inserted directly into concrete or other hard surfaces. After the modules are opened, two copper mesh contact areas are placed on the surface under test and moistened with water to establish electrical contact. The earth nets modules can be clicked onto the supplied test lead reels, forming a single assembly.
Optional Bluetooth communication can be added to the FT6041-91 with the Z3210 Bluetooth Adapter. This allows measured values to be transferred wirelessly 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 FT6041-91 was developed in Japan and is manufactured at HIOKI’s own production facilities in Nagano Prefecture, Japan.
• FT6041 Earth Resistance Meter
• FT9847 Signal Induction Clamp
• CT9848 Signal Detection Clamp
• 2 × L9840 Auxiliary Earth Spikes
• L9841 Test Lead, black, 4 m
• L9845-31 Test Lead Cable Reel, yellow, 25 m
• L9845-33 Test Lead Cable Reel, blue, 25 m
• L9845-52 Test Lead Cable Reel, red, 50 m
• 2 × L9846 Earth Nets Modules
• L9787 Test Lead Set
• C0208 Carrying Case
• C0209 Tote Bag
• Instrument Protector
• 4 × LR6 AA Alkaline Batteries
• Instruction Manual
• Operating Precautions
• Z3210 Bluetooth Adapter
• 9772 Straight Pin Type Lead
• 9467 Large Clip Type Lead
• FT6041 Earth Resistance Meter
• FT6031-50 Earth Tester
• FT6031-90 Earth Tester
• FT6380-50 Earth Ground Clamp
• FT6380-90 Earth Ground Clamp
• L9844 Test Lead Set
• L9843-51 Test Lead, yellow, 50 m
• L9843-52 Test Lead, red, 50 m
• L9842-11 Test Lead Reel, yellow, 10 m
• L9842-22 Test Lead Reel, red, 20 m
• 9050 Earth Nets
