Apps · Program planning
PdM Program Setup
A planning tool for program managers and reliability engineers. Describe your assets and their criticality; get recommended techniques, sensor counts and types, mounting, data settings and measurement intervals, with a focus on IIoT and wireless sensors.
Mounting sets the usable frequency range
Permanent wireless sensors should be stud-mounted on a spot-faced surface, or epoxy-bonded where drilling is not allowed. Magnets are for pilots and temporary checks. Indicative ranges; the sensor data sheet and surface preparation decide the real limit.
MEMS or piezoelectric?
| MEMS | Piezoelectric | |
|---|---|---|
| Low frequency | Down to 0 Hz, but higher noise floor | Rolls off below about 0.5–3 Hz (special low-frequency models to about 0.1 Hz); low noise |
| High frequency | Commonly a few kHz, better devices to about 6–10 kHz | 10–15 kHz or more |
| Power and cost | Very low power, low cost | More power and cost |
| Use for | Standard-speed pumps, fans and motors on wireless nodes | Slow and high-speed machines, gearboxes, critical assets |
Data settings rules of thumb
- Fmax: at least 10× running speed for unbalance and misalignment; about 40× speed or 4× BPFI for rolling bearings; 3× gear mesh for gearboxes; 3× vane or blade pass.
- Sampling rate: 2.56 × Fmax.
- Lines: enough that resolution (Fmax ÷ lines) is a tenth of running speed or finer, so each record covers at least ten revolutions.
- Record length: lines ÷ Fmax seconds. Slow machines need long records.
- Envelope band: typically about 1–10 kHz on standard-speed machines, 0.5–5 kHz on slow ones, to catch bearing impacts.
- Units: velocity (mm/s RMS) for overall condition; acceleration (g) for bearings and gears; displacement for slow shafts and sleeve bearings.
Sensor placement
- On the bearing housing, in the load zone, with the shortest rigid path to the bearing. Never on fan covers or thin guards.
- Minimum practical coverage: drive-end bearing of the motor and of the driven machine; gearbox input and output.
- Horizontal machines: radial horizontal often shows the most vibration; axial shows misalignment. Vertical machines: two radial directions at the top bearing.
- Same point, direction and mount every time; label each location.
Learn the reasoning in the vibration sensors and IIoT and wireless chapters of the PdM Program Guide.
How the recommendations are made
- Criticality. Each asset gets a tier, either chosen directly or scored from weighted consequences (safety, environment, production, cost, quality) multiplied by likelihood. A worst-case safety or environmental score raises the tier.
- Techniques. Each failure mode you select maps to the techniques that detect it as primary or supporting. Techniques that cannot apply are removed (no motor current analysis without an electric motor, no oil analysis on grease). Tier C assets keep primary techniques only.
- Connection. With the hybrid approach, tier A machines with sleeve bearings or very high power get a wired protection system; other monitored assets get wireless sensors. Tier C assets go on a portable route unless access is hard or hazardous.
- Sensor points. Bearing positions come from the driver, gearbox stages and driven machine. Coverage decides whether every bearing or only the drive ends get sensors.
- Sensor type and settings. For each point, shaft speed, rolling elements, gear teeth and vanes set the lowest and highest frequencies of interest. That sets Fmax, lines, record length, the envelope band, MEMS or piezo, and the mounting.
- Schedule and battery. Wireless schedules start from the tier (tier A: overall values every 10 minutes, 6 waveforms a day) and are reduced until the illustrative battery estimate meets your target.
This tool is a structured starting point for planning and budgeting. It does not replace a site survey, the sensor supplier's data sheets, or review by a qualified engineer. For the reasoning behind each rule, read the PdM Program Guide.