Overview of Non-Standard Sensors for TKM-459 Ultrasonic Hardness Testers

Ultrasonic hardness testers TKM-459 are modern portable devices for rapid and highly accurate measurement of the hardness of metal products using ultrasonic contact impedance (UCI).

The TKM-459 series ultrasonic hardness tester, in any configuration, includes the standard “A” sensor, designed for a load of 5 kg (50N). This type of sensor is capable of handling most tasks related to the hardness testing of metals and alloys, and it is usually sufficient for the job.

For more specific tasks and specialized hardness testing studies, we have developed sensors of types “H”, “C”, “K”, and “AL”.

Features of ultrasonic sensors “H”, “C”, “K”, and “AL”

The “H” sensor is optimal for measuring the hardness of thin electroplated coatings (chrome, copper, nickel, zinc, tin) with a thickness of 30 μm or more, as well as products made from fine-grained materials.

Due to its minimal load of only 1 kg (10N), this sensor leaves virtually no trace on the surface, making it suitable for measurements on small and thin-walled products. It is primarily purchased for use in the metalworking, machine-building, and electronics industries.

The “C” sensor with a load of 10 kg (100N) is intended for testing thick-walled and large-sized products. Measurements can be performed on unprepared surfaces with a roughness up to the 5th grade (Ra 3.2). It is the only ultrasonic sensor for TKM hardness testers that is suitable for working with corroded surfaces of metal objects.

The “K” sensor has a minimal body height (76 mm) compared to other sensors. It is used for hardness testing of surfaces inside pipes, tanks, and other products with limited space and a diameter of 80 mm or more. The sensor can be manufactured with various loads: 1, 5, or 10 kg.

The “AL” sensor features an extended rod length of 65 mm. The non-standard design was specifically developed for hardness testing between gear teeth, in grooves, holes, and other hard-to-reach locations with small diameters—starting from 10 mm in its standard form and from 5 mm with the tip removed.

The “AL” sensor can be supplied with the required load to solve specific tasks—1, 5, or 10 kg.

Important to note!

• All sensors are interchangeable. The customer can easily supplement the configuration of a previously purchased TKM-459 hardness tester with the required sensor type.
• When the sensor is perpendicular to the surface, measurements can be performed in any spatial position, which is important in production conditions or in the field.
• To work with any ultrasonic sensor, the control zone area needs to be only 1 mm.
• The protective tip of the “A”, “H”, “C”, and “AL” sensors can be removed, allowing measurements in narrower and deeper holes or grooves. However, it is important to avoid contact between the sensor rod and the surrounding walls of the product.
• The cable connecting the sensor to the hardness tester's electronic unit is connected via a built-in Lemo connector. If the cable is damaged or worn, it can be easily replaced.
• The “A”, “H”, and “C” sensors can be used with a specialized “U-459” attachment for stable positioning on flat or cylindrical surfaces.
• For the TKM-459 ultrasonic hardness tester with “A”, “H”, and “C” sensors, a T4 measuring stand has been developed, which ensures maximum convenience for the operator and minimizes human error. It is recommended for hardness testing of large batches of similar products and small-sized objects.

Key Parameters of Ultrasonic Sensors