1.Introduction
    GD-C Natural VLF water detector is a design that refers advanced technology home and abroad, solves great subjects on shielding and selective signal processing to amplify in complex natural electric field, and also does multiple anti-jamming as well.

    GD-C Natural VLF water detector is similar to traditional resistivity prospector generally, the biggest difference is applying natural electric as field source and removing heavy power supply, the total set is no more than 5kg. Its main features are simple operation, easy to carry, high accuracy, fast speed, flexible array etc. The speed is 10 times more than traditional DC resistivity prospector, and it is your useful assistance in ore prospecting. More than 20 years’ practice proves that it is a state-of-the-art portable earth resistivity meter and gains customers’ common praise.

2. Principle

     GD-C Natural VLF water detector uses relative parameters like resistivity variation produced by natural electrical field and different geologic structures(underground water is benign conductor)to determine the water(bedrock fracture water, carst water, pebble bed water etc.) we are seeking. It can know relative information like water location, depth and water outflow etc. Comparing to other water detectors, it has obvious advantages: fast, high accuracy, check full information, portable, simple operation and so on.

3. Main application

    1. Applied in underground water detection to meet the demand of drinking water, industrial usage and agricultural irrigation.
    2. Widely used in metal ore prospecting, non-metal ore's detailed and general survey to decrease the venture of mineral investment and improve exploration success rate and scientificalness.
     3. Also used in engineering geological prospecting, disaster geological detect, coal goaf, archaeological mining, city exploration, non-metal pipe survey as well.

4. Main features

   1. Fast and high efficiency:
Complete about 4000m profile measurement in one day to realize geological abnormity in different depth, the prospecting speed and efficiency is improved about 10 times more than traditional resistivity method.   

    2. Easy to carry:
Without heavy power supply, it uses earth natural electromagnetic field as signal source, and the weight of complete set is less than 5kg so easy to carry and use.

    3. Easy operation:
Equipment is automatically controlled by micro PC. You can learn its operation in 10 min. It will take 2h for person without prospecting experience to finish the relative training.

   4. Good precision and high accuracy:
It will do measurement with resolution up to 0.001mV, high precision ±50%.
    5. Strong anti-jamming capability:
You can get good curves result even in noisy road and high electric jamming area for signal via frequency selector and digital processing.

   6. Flexible array—traditional and unique array method:
It has multi-array measurement method: traditional and original electrode array method, which has good geological effect and easy explanation. It makes big achievement in solving problems about the direction, depth and thickness of ore vein.

5. Technical parameters
   1.Automatic noise reduction, super anti-jamming.
   2. Measurement of 3 frequency (25Hz, 67Hz, 167Hz) or 30 frequencies measuring synchronously.

   3. Operation functions are all displayed on LCD, you can see them directly.

   4. Automatic measurement, data storage and curves mapping. Data record is no need. The data will not loss even power off.
   5. The data storage capacity: 30 measured curves in three frequencies and 30 measured curves in multi-frequencies measurement.

   6. Curves and data can be displayed; you can also transmit data by USB port and map or print in computer.

   7. Rechargeable batteries to supply power.
   8.Electrode detection and power monitoring function
   9.Measuring range: 0.001mV~255mV (exchange range automatically)
   10.Measurement resolution: 0.001mV
   11.Measurement accuracy: ± 5% ± 3 bytes
   12.Input impedance: ≥ 10MΩ
   13.Whole operating temperature: -10 °C~+50 °C
   14.Working Humidity: 95%
   15.Whole weight: 1.98Kg (batteries excluded), size: 24CM*13CM*16CM