WDJD-4 Multi-function Digital DC Resistivity/IP Meter is our new generation model with 32 single-chip and 24 bit A/D technology on the basis of years of experience of design and manufacture, which could carry on Res and IP survey at the same time. It features multiple functions, high accuracy, fast speed, high reliability and excellent expandability. Measured data of WDJD-4 can be processed by other multi-electrode resistivity software, which makes the interpretation more convenient.

The single WDJD-4 can conduct general electrical resistivity/IP survey with twist pair wire, iron electrodes and power source. If WDJD-4 is used together with WDZJ-4 multiplex electrode switcher multi-electrode cable, electrodes and power source, it can conduct not only general electrical resistivity/IP survey but also multi-electrode 2D Resistivity imaging.

Function
Res/IP sounding
Res 2D imaging survey

Main Features:
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Transmitting unit and receiving unit are of all-in-one design, portable and lightweight.
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CMOS large-scale integrated circuit, special stand-by mode, compact size, low power consumption. System turns off WDJD-4 mainframe automatically if there is no operation in 10 minutes.
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High anti-interference performance and precision, integrated with multistage wave filtration and signal enhancement technologies.
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In good condition, multi-electrode imaging function can complete measurement of 552-data-points cross section in 15 minutes.
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Automatically achieving compensation of self-potential, drift and electrode polarization.
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Receiving unit support transient over-voltage protection, transmitting unit supports over-voltage protection, over-current protection and AB open-circuit protection.
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Simple calculator fulfills calculation of geometric factor and other calculations on the spot.
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For general resistivity and IP survey function, 9 types of electrode arrays are available. Electrode distance (namely “Schedule”) can be inputted or called. Geometric factor K can also be generated automatically or calculated manually.

For multi-electrode 2D resistivity imaging, up to 18 electrode arrays are available. It could scanning measure according to fixed section (including AMNB, ABMN, AMBN, AMN, MNB, A-MN-B, Sp M, Sp MN, charge M, charge MN) or continuous rolling scanning measure according to variable section (including A-M, A-MN, AB-M, AB-MN, MN-B, A-MN rectangle).
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Schedule: the schedule can memorize 100 groups of electrode distances, avoiding repetitive input. Or you just input a schedule Id and step to call the corresponding electrode distances.
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Earth resistance inspection: ground condition can be inspected at any time.
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Mass data storage: WDJD-4 can memorized 3500 readings of data for resistivity and SP survey; 2250 readings of data for resistivity and IP survey ; 43680 readings of data for multi-electrode 2D resistivity imaging Ⅰand 21840 readings of data for multi-electrode 2D resistivity imaging Ⅱ.
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All parameter and data are under power-failure protection; and thus data will not be lost even thought the system shuts down accidentally.
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RS-232C port enables it to transfer data to computer.
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Diagnostic program finds fault or failure and damaged parts quickly and accurately.
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Sealed constitution: featuring waterproof and dustproof design, long life time and so on.

Technical specifications:

Receiving part

Voltage channel: ± 6 V 
Survey precision: if Vp≥10 mV then ± 5‰ ± 1 LSB, if Vp < 10 mV, then ±1% ± 1 LSB 
Input impedance: ≥50MΩ 
Apparent polarizability precision: ±1% ± 1 LSB 
SP compensation range: ±10 V 
Current channel: 6 A, survey precision: if IP≥ 10mA then ± 5‰ ± 1 LSB, if IP < 10 mA, then ±1% ± 1 LSB 
Suppression: ≥90dB for 50Hz industrial frequency 

Transmitter part

Voltage maximum: 1100V 
Current maximum: 6A( when voltage ≤ 900V ) 
Pulse width: 1～ 60s, duty ratio 1:1 
Other

Operating temperature: -10℃～50℃, humidity: 95 %RH 
Memory temperature: -20℃～50℃ 
Instrument power: eight D size batteries (or same specs nickel-cadmium battery) 
Complete appliance current: ≤ 55mA 
Weight: ≤ 4.5Kg 
Dimensions (L×W×H): 270mm X 246mm X 175mm