Class Instrumentation Ltd


Class Instrumentation was established in 1996.  Since that time the company has grown into a global leading player in ultrasonic, non-destructive testing and survey equipment.

We pride ourselves in our record of innovation and development - each product perfected in partnership with our customers, creating instruments that make their jobs safer and their results reliable and accurate.

All of our units are designed and manufactured in full accordance with ISO9001: 2000, guaranteeing the quality of each of our products.  We work closely with The American Bureau of Shipping (ABS) Classification Society, from whom we have accreditation to produce Type Approved products for the marine industry.  We are corporate members of The NFPA, The International Institute of Marine Surveyors (IIMS) and The Nautical Institute.  We are fully committed to the marine sector where we continue to create products that are fully compliant with all IMO, IACS and SOLAS standards and regulations.

Cargo-SafeTM ultrasonic hatch cover tester

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
Cargo-SafeTM ultrasonic hatch cover tester

DOOR-SAFE™ Water-Tight Door Tester

The Class Instrumentation Ltd Door-Safe™ can be used to determine the integrity and water-tightness of

  • water-tight doors in the offshore, marine and aero-space industries
  • water-tight hatches
  • windows
  • Navy supply doors
  • shipping containers
  • cars
  • yachts
  • caravans

Please note, this unit is not for use on cargo hatch covers.  If you wish to know the integrity of hatch covers, please see our Cargo-Safe unit.

DOOR-SAFE™ Water-Tight Door Tester

PLI Digital Portable Liquid Level Gauge

With all the features of the original PLI , the fully American Bureau of Shipping (ABS) Type Approved PLI Digital has the ability to take a reading from cylinders in poor condition, or suffering from a layer of rust.  It also has an in-built thermometer (in both C & F), an easy-to-read digital display, one-button-set-up function for faster cylinder testing and smart plug, which enables the signal strength to be monitored by an audio signal from an internal speaker.

PLI Digital Portable Liquid Level Gauge

PLI Plus Liquid Level Indicator

We stock the reliable PLI Plus 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 Plus 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 Plus 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.

PLI Plus Liquid Level Indicator

Touchstone 1 Ultrasonic Thickness Tester

The Touchstone 1 is a high performance, low cost, simple to use handheld Touchstone 1 ultrasonic thickness tester. We supply the innovative Touchstone 1 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

Touchstone 1 Ultrasonic Thickness Tester

Touchstone 2 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 Touchstone 2 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 
Touchstone 2 Coating Thickness Gauge

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.

Sonic Leak Detector

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. 

Cabin-Safe Boat Survey Tester
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