Class Instrumentation Ltd


We supply the comprehensive Cargo-SafeTM ultrasonic hatch cover tester. It is a system designed for testing the water integrity of cargo hatch covers. It enables the quick and easy location of leaks and gaps in hatch seals and coamings. The innovative Cargo-SafeTM ultrasonic hatch cover tester is ABS type approved marine surveyor equipment is accepted by P&I clubs and conforms to IMO regulations and IACS recommendations. It is an invaluable tool for loss prevention marine survey work and cargo hold surveys.

The Cargo-SafeTM kit includes:

  • Ultrasonic transmitter unit
  • Receiver unit
  • Hard hat compatible headphones
  • 2 Flexible inspection microphones (1 spare)
  • Protective IP66 storm-proof leather cases with neck and waist straps for hands free operation
  • Telescopic microphone extension, up to 1.15m (45")
  • Full operating instructions
  • Emergency microphone lead
  • Emitter, microphone and extension arm tester
  • Batteries and global charger (with 12V car adaptor)
  • 12-24V auxiliary power input lead
  • 450 x 320 x 100mm (17.7" x 12.6" x 3.9") foam-lined black polymer carry case

PLI Liquid Level Indicator

We stock the reliable PLI portable liquid level indicator gauge designed to determine the liquid level of CO2, Halon, FM200, Propane and any liquefied gas under pressure without the need to move or weigh the cylinders. There is no reduction in health and safety, and the risk of gas leaks during servicing is eliminated as cylinders remain active and in situ.

The diverse PLI portable liquid level indicator is suitable for use on cylinders, pipe-work and any single skinned holding vessel with up to 25mm thick walls.  It will also indicate the level of oil or water in a container or tank. The PLI gives accurate results by generating an ultrasonic sound wave that travels through the container and into the liquefied gas or fluid. The pulse responds differently to the presence or absence of liquid, indicating the level of the liquid.

Cabin-Safe Boat Survey Tester

We supply the reliable cabin-safe boat survey tester as a smaller and less powerful version of the CARGO-SAFE™ unit. The efficient cabin-safe boat survey tester detects the source of leaks in pleasure craft, yachts, cars and caravans. The transmitter unit is placed inside the vessel and the receiver microphone is used to inspect seals, doors, windows and deck fittings on the outside for places of potential water ingress. Ultrasound will be detected on the exterior of the craft if any hole exists. 

Ultrasonic Thickness Tester

The Touchstone 1 is a high performance, low cost, simple to use handheld ultrasonic thickness tester. We supply the innovative ultrasonic thickness tester suitable for use in a variety of NDT applications. It is capable of measuring most engineering materials including plastic, glass, copper, cast iron and aluminium as well as a variety of steels.


Thickness range: 1.0 to 199.9mm
Resolution:  0.1mm
Accuracy: ±0.1mm
Velocity Adjustment:  0 to 999metres/sec
Display:  12.5mm high LCD screen

Coating Thickness Gauge

The Touchstone 2 is a comprehensive coating thickness gauge requiring no couplant that will work on rough surfaces in any condition. The coating thickness gauge uses the magnetic properties of the substrate material to determine the coating thickness. Its effect sensor will measure an assortment of non-magnetic coatings on ferrous substrates including paint, plastic, stainless steel, galvanised zinc, aluminium and tin.


  • Highly accurate hall effect sensor
  • Measures any non-ferrous coating
  • Measures up to 8mm of coating
  • Simple calibration and operation 

Sonic Leak Detector

Our sonic leak detector is an affordable instrument allowing for the rapid detection of pressurised gases escaping from any form of plant system or leaks in vacuum systems. The sonic leak detector will quickly detect the ultrasonic "noise" generated by a leak. The red laser pointer accurately and safely pinpoints the source of the leak while the wide range of frequencies are detected by the unit ranging from 20 to 100 kHz. The sonic leak detector significantly reduces leak detection times and produces substantial cost savings.

GM-1 Gauss Meter/Tesla Meter

Our GM1 Gauss meter/Tesla meter is an easy to use method of measuring DC magnetic flux and direction using a solid-state hall-effect sensor. The diverse GM1 Gauss meter/Tesla meter is a lightweight, hand-held gauge designed to provide accurate results and is perfect for a multitude of applications including:

  • Residual magnetic fields on bearings and machinery, now subject to regulation
  • Residual magnetic fields on welds
  • Residual magnetic fields on parcels and packages
  • Residual magnetic fields on ships’ cargo
  • Computer disk drive actuators
  • Loudspeaker air gaps
  • Electric motor air gaps
  • Transformer stray field measurements
  • Bending magnets
  • Non destructive testing (magnetic)
  • Goods inward and quality assurance inspection
  • Magnet calibration

Technical Support

We supply our high quality products complete with free technical support for the life of the unit. Our units do not require annual calibration by the manufacturer, but we do recommend that every five years units are returned to us for a service.

We offer an efficient repair service for all our products, but we do suggest you contact our technical department before returning a unit as we may be able to help without the unit being shipped to our factory. We will also ship to you any replacement components you may need. Contact us for a full list of available spare parts.

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