EXLRT - MK Test Systems XLR-9703-01 – ExLRT Loop/Joint Tester for Select Boeing Aircraft

The ExLRT (XLR-9703-01) is a lightweight aircraft loop and joint resistance tester used for non-intrusive AC testing of bonding loops and structural joints. It supports accurate resistance measurements without breaking the circuit, making it ideal for fuel tank environments and other sensitive aircraft areas. Designed for aviation maintenance applications, it improves efficiency and reduces downtime during routine inspections.

Yes. The ExLRT is lightweight and specifically engineered to support single-operator loop testing and joint resistance testing workflows. Weighing approximately 6.6 lbs (3 kg), it reduces handling strain compared to heavier legacy loop resistance testers. This makes it easier for technicians to conduct resistance testing in tight aircraft spaces or on the flight line, improving both safety and operational efficiency.

The ExLRT is certified for use in potentially hazardous environments and is approved under ATEX (EU), IECEx (International), and QPS (USA and Canada) standards. These certifications support safe operation in explosive atmospheres, including fuel vapor zones. To maintain intrinsic safety compliance, the unit must be operated self-powered, without tethered power or data cabling attached in hazardous areas. This ensures safe, compliant use of aircraft test equipment during maintenance procedures.

Intrinsic Safety is a protection method that limits electrical and thermal energy to prevent ignition in hazardous environments. For loop resistance testing equipment, this means the ExLRT is certified as intrinsically safe in accordance with global standards, making it suitable for use in fuel tank and vapor-prone areas. Unlike legacy LRT tools, the ExLRT is specifically designed to meet modern intrinsic safety requirements.

ExLRT Record Mode allows technicians to capture and manage test data directly within the loop and joint tester. This reduces overall testing time and minimizes the risk of transcription errors commonly associated with manually recording resistance measurements on task cards. Test results can be stored on the unit itself or uploaded to a PC for further analysis and documentation. The feature is easily accessed through the on-screen menu system.

Yes. The XLR-9703-01 ExLRT Loop/Joint Tester includes a digital manual, which can be supplied upon request. Additional resources such as product brochures, help guides, how-to tutorials, instructional videos, certificates, and technical documents are also available. These materials help support proper operation, calibration, and safe use of the aircraft test equipment.

The XLR-9703-01 ExLRT Loop and Joint Tester is backed by a 12-month manufacturer’s warranty from the date of delivery to the customer’s site. This warranty provides coverage against manufacturing defects and supports the long-term reliability of the aircraft loop resistance tester.

No. Although both the BLRT and ExLRT use MK52 couplers, their loop and joint cables are not interchangeable. While the cables may appear similar, the connectors differ and are specifically designed for each unit. For proper resistance testing, accuracy, and safety compliance, use only cables intended for the ExLRT.

Although couplers and clamps may look similar, they serve different functions in aircraft testing. Clamps are mechanical devices that apply physical pressure to pass a DC electrical signal into the unit under test (UUT), commonly used in DC bond testing applications such as 1A, 10A, or 150A bond tests.

Couplers, on the other hand, magnetically transfer an AC electrical signal across an air gap. This allows non-intrusive AC loop and joint resistance testing without direct electrical contact. The MK52 couplers used with the ExLRT are specifically designed for AC measurements. It’s worth noting that commonly referenced i400 “clamps” are technically couplers, which can understandably cause confusion.

No. The ExLRT does not require jumper cables to operate. While the battery is necessary for self-powered operation – particularly in hazardous environments – jumper cables are not mandatory for standard testing procedures. However, certain accessories may be recommended depending on the specific maintenance workflow or aircraft application.

Battery replacement must always be performed in a safe, non-explosive environment. The ExLRT's intrinsic safety is assured only when the battery is correctly installed and the battery door is fully closed and latched.

To replace the battery:

1. Power off the unit using the button located under the handle on the rear of the display.
2. Use the supplied red hex key to loosen the quarter-turn screws on the back panel.
3. Open the battery door and slide the latch lever to the left to release the battery.
4. Insert or remove the battery without applying force.
5. Slide the latch back to the right to secure the battery, close the door, and tighten the screws.
6. Restart the unit using the power button.

A step-by-step instructional video is also available for additional guidance.