Piezoelectric resonators (abbreviated RP) is a technical term adopted at our company. In ultrasonic control the resonator is responsible for the conversion of the electrical signal into mechanical vibrations (sound waves) and vice versa, but structurally does not contain additional components for connection, except for the contact group, as it is designed for installation in the transducer blocks, being a replaceable element of the block as it wears out.

Main characteristics of RP resonators:

• The used PZT type piezoceramic element provides high sensitivity and stability of operation.
• The flat shape of the radiating surface guarantees a uniform radiation pattern.
  • Operating temperature range -40°C to +50°C.
  • Resistant to humidity up to 98% at 35°C without condensation.
  • Resistant to sinusoidal vibrations in the frequency range from 10 to 55 Hz with an amplitude of 0.15 mm as well as to single shocks with a peak acceleration of 50 m/s²

Technical Parameters:

• The effective frequency of the echo pulse is (2.5 ± 0.25) MHz.
• The input angle and deviation from the nominal value are provided at the process level.
• The pulse double conversion ratio and noise level comply with the regulations.
• The width of the radiation pattern is provided by the design features of the resonator

Reliability and service life:

• Resonators are non-repairable products.
• Average time to failure under normal operating conditions is at least 1000 hours at a scanning speed of 0.5 m/s.
• The rejection criterion is non-compliance with technical requirements.

Advantages of our resonators:

1. Original flooded resonator manufacturing technology with state-of-the-art components.
2. High climate resistance and degree of durability.
3. Possibility to sound the resonator in several directions
4. High sensitivity with a relatively small noise response.
5. Compatible with different types of flaw detectors
6. Extended resonator nomenclature covering all known sounding patterns used on railroads.
7. There are no hazardous and harmful production factors affecting labor safety and the environment in the RP.

STRUCTURE AND DECIPHERING OF THE RP DESIGNATION

Resonators, depending on their design and purpose, are divided into several groups:

– straight separate-and-separate;

– inclined combined single-element PSDs

– inclined combined two, three and four element PSDs

Resonators are abbreviated as:

RP RS-1,2,3

RP- Piezoelectric resonator

RS – Split and Combined

1,2,3- Applicability to the flaw detector

RP- α° – Input angle (single element)

RP- α°/α° – Input angle (two-element)

RP- x°/x°× α° – Angle of rotation between acoustic axes

For three-element tap-changers, the input angle is also indicated by “slash”, e.g. 70/70/70. For counter-mounted tap changers, the designation with a “multiplication” sign is allowed, e.g. 4×70.

PSD labeling

The marking of the PSD contains: the company logo, conventional designation of the PSD, serial number, year (last two digits) and quarter of manufacture. The abbreviated designation is allowed. If necessary, polarity or numbering of contacts can be marked on the plane of the resonator in accordance with the electrical scheme of the transducer unit.

Example of marking

Nomenclature of serially produced resonators and their main technical characteristics (see table)