Sensor Technology Ltd.’s BM500 series of piezoelectric ceramics contains three soft PZT formulations. They are all Navy Type materials; BM500, BM527 and BM532 correspond to Navy Type II, Navy Type V and Navy Type VI respectively. The BM500 series ceramics are lead zirconate titanate and, in general, offer high coupling coefficients and large piezoelectric charge constants. However, each piezoelectric ceramic offers some unique performance property, described below.

BM500 – PZT-5 (NAVY TYPE II)

BM500 is the piezoelectric ceramic of choice for the majority of passive sensor applications. We use it for most of our hydrophone designs. In general, PZT-5 materials are the best choice for converting a mechanical input into an electrical signal. For example, in the case of a hydrophone, the ceramic converts an incoming pressure wave into a voltage output.

BM500 can also be used for transmission, which makes it useful for send/receive hydrophone designs. However, it has a high dissipation factor which leads to electrical losses and potentially damaging heat build-up. It is suitable only for low duty cycle, low power transmission applications.

BM532 – PZT-5H (NAVY TYPE VI)

BM532 is a modified version of BM500. It has significant increases in both the dielectric and piezoelectric charge constants (i.e. d constants). As a result, it is the piezoelectric ceramic of choice for actuator applications requiring large mechanical displacements.

It is sometimes selected for use in circuits requiring a high capacitance ceramic. For example, despite its high dissipation factor is sometimes used for small, battery powered transmit applications.

BM527 – PZT-5J (NAVY TYPE V)

BM527 has dielectric and d constants larger than BM500 but smaller than BM532. It provides a compromise between the two materials.

Hard PZT piezoelectric ceramics can endure higher drive voltages and more demanding duty cycles than soft PZT materials. Hard PZT is ideal for high power, drive applications.

Industrial applications of hard PZT rely primarily on two standard materials: Navy Type I (PZT-4) and Navy Type III (PZT-8). Sensor Technology Ltd. manufactures these two piezoelectric ceramic formulations as BM402 and BM802 respectively.

BM802 – PZT-8 (NAVY TYPE III)

With an extremely low loss factor and high quality factor, BM802 (Navy Type III) is the material of choice for high power transducers. It is commonly used for sonar systems and other high power acoustic transmitters. These tend to be lower frequency applications, generally falling within the audible range (< 20 kHz).  However, it is also chosen for high power ultrasonic applications. These include ultrasonic welding, ultrasonic cleaning and megasonic cleaning. These high power applications often occur at frequencies into the hundreds of kilohertz range (i.e. 100,000 Hz and higher). As the name suggests, megasonic cleaning occurs at frequencies around 1 MHz.

BM402 – PZT-4 (NAVY TYPE I)

BM402 (Navy Type I), commonly referred to as PZT-4, offers a valuable balance between hard PZT, such as BM802, and soft PZT. It has a low dielectric loss, making it suitable for high power, drive applications.  At the same time, it has excellent piezoelectric properties, making it useful in receiving applications as well. PZT-4 is generally the first choice for transducers that will both transmit and receive. BM402 provides performance comparable to that of other common PZT-4 materials, including Channelite-5400 PZT.

BM200

Our unique BM200 piezoelectric ceramic is the even harder than BM802 (Navy Type III). It is an excellent candidate for highly repetitive, quasi-static loads and extreme drive applications.