A Look Back: The History of Prisma DI

Did you know that PrismaTibro has been manufacturing digital instruments to measure crankshaft deflection since the late 1980s? In the beginning, we manufactured a model called RO-3. Its appearance differed significantly from today’s models – it was shaped like a small box.

The 1990s

In 1994, RO-3 was replaced by Prisma DI-4 after a period of intense development work. For Prisma DI-4, we changed the circuit board and introduced a new outer casing in red. We also changed the designation to DI, Deflection Indicator.

In 1998, Prisma DI-4C was launched, introducing the possibility to save readings and transfer them to a computer for further processing.

The 2000s

The next generational shift occurred in 2006 when we introduced Prisma DI-5. The circuit board was redesigned, and the cable and transducer became two separate items, making it easier to replace the transducer when worn. A rechargeable Li-Ion battery was also included.

One year later, Prisma DI-5C was launched, featuring updates such as a USB cable for data transfer.


The Prisma DI-5 series is widely used by engineers worldwide, on vessels and in power plants. Some changes have been made, but the smart, reliable, and long-appreciated technology remains the same.

Do you want to optimize your measurements?

> Contact product manager Harut Pdrossian.