HD ENV is a novel approach to the task of detecting gear and bearing deterioration in very early stages. By combining low noise hardware design and patented algorithms for digital signal processing with a standard vibration transducer (accelerometer), it is possible to extract relevant gear and bearing information from a noisy environment with exceptional clarity. Historically, gear and bearing damage detection using standard velocity readings (i.e. overall velocity values) could – in the best of cases – reveal severe damages in very late stages, thus resulting in very limited planning horizons. At best, a trend of increased velocity RMS values could be used to avoid unplanned stops.

Adding spectrum analysis based on velocity readings could reveal gear and bearing damages earlier than in the very late stages, but it was still a rather crude tool. When vibration enveloping was introduced several decades ago, it became possible to detect damages in earlier stages than before, and it then became relevant to talk about realistic pre warning times. With vibration enveloping, it was possible to extract information coming from gears or bearings even if the transducer signal was dominated by low frequency content typically originating from unbalance forces.

HD Technology (HD = High Definition) was introduced for the first time in 2010, when the SPM HD method (Shock Pulse Method High Definition) was launched. One of the goals of SPM HD was to detect bearing and gear damages on applications running at low or ultra-low rotational speeds (from 60 down to below 1 RPM). At these low RPMs, traditional vibration technologies were difficult – in most cases even impossible – to use with success, while SPM HD produced meaningful and generally excellent results. Since then, a large number of successful application cases utilizing the SPM HD method, especially low RPM applications, have been documented.