Mitech MTH-7D DC Spark Leak Detector

Mitech MTH-7D DC Spark Leak Detector

Product Overview

The Mitech MTH-7D is a high-performance digital DC spark leak detector designed to detect cracks, pinholes, blisters, and other flaws in anti-corrosive coatings on conductive substrates. Using the principle of high-voltage pulse discharge, this instrument provides a quick and intuitive method for identifying coating defects with visible sparks and an audible alarm. Powered by a high-capacity battery, the MTH-7D is ideal for on-site field operations without relying on AC power, making it a trusted tool in oil and gas, petrochemical, metal pipe, enamel, and rubber industries.

Key Features

• Wide Range of Applications:
  Detects coating defects on glass linings, epoxy coatings, rubber linings, glass-reinforced plastic (GRP), and more—across pipelines, tanks, hulls, valves, cables, and castings.

• Battery-Powered for Field Use:
  Operates independently of 220V AC power—perfect for remote or mobile testing scenarios.

• Digital Voltage Display:
  LCD screen clearly displays the output pulse voltage (KV) for real-time monitoring.

• Adjustable Output Voltage:
  Pulse voltage easily controlled via rotary knob to suit different coating thicknesses and inspection requirements.

• Multiple Probe Options:
  Includes two types of probes for various inspection surfaces; custom probe designs available for unique applications.

• Lightweight & User-Friendly:
  Compact and ergonomic design with low power consumption, simple controls, and intuitive operation.

Working Principle

The MTH-7D applies pulsed high voltage to an insulated conductive surface. If a defect such as a crack, pinhole, or blister is present, the pulse breaks through the air gap and produces a visible spark at the fault location. Simultaneously, the system triggers a sound and light alarm, providing quick and accurate defect detection in anti-corrosion coatings.

Typical Applications

• Oil and gas pipelines

• Chemical processing vessels

• Rubber-lined tanks and pipes

• Enamel coatings

• Cable sheaths

• Ship hull coatings

• Steel pipe linings and valves

Operating Conditions

• Environment must be dry and free of corrosive gases or moisture

• Suitable for room temperature operation

• Ensure proper grounding of the test object before use

Operating Instructions & Precautions

• For small metal objects, elevate the object at least 20 cm on an insulating base, and connect the ground wire properly.

• For large surfaces with good grounding, directly attach the ground wire to the earth.

• Use insulated gloves and avoid touching the probe or object during operation to prevent electric shock.

• Keep the coating surface dry and clean. Any conductive dust may cause false alarms.

• Avoid using the device during charging to protect battery health and ensure safety.

• Maintain an optimal probe-to-surface distance. Too close can damage the coating; too far may exceed detection range.

• Select detection speed based on the coating thickness and type to ensure effective measurements.

Maintenance Tips

• Avoid mechanical damage or exposure to moisture, heat, or corrosive chemicals.

• Remove the battery when not in use to prevent leakage or damage.

• Clean the instrument surface with a soft, dry cloth after use.

• Never disassemble the unit yourself—contact Mitech for any repair or service needs.

• Regularly check fuses and grounding to ensure proper operation.

• Do not allow the probe to contact the ground—this may result in severe damage to the internal electronics.