Vibration Monitors & Sensors: A Buyer Guide

Buy the measurement your maintenance decision needs

A vibration monitor is useful when its output helps the maintenance team decide what to inspect next. For a steady-speed fan, a repeatable trend may be the immediate requirement. A slow gearbox, variable-speed pump or intermittent compressor can need a different measurement window and more operating context. Begin with the machine and the question, then compare sensor and service packages.

addanode provides condition-sensor integration, operating trends and maintenance reporting. The project quotation identifies the acquisition equipment, installation and specialist interpretation included. A sensor being online establishes connectivity; a representative signal and a documented mounting position establish what the maintenance team can actually examine.

What do different outputs let you inspect?

A vendor's dashboard may display a detailed chart without offering the underlying data in a usable export. Ask for a representative file before choosing the service. Confirm whether the price includes raw or summary data, historical retention, automated indicators and access by your machinery specialist. Different packages can use similar sensors while delivering substantially different evidence.

Sample rate and reporting interval are different

A reading sent every 15 minutes does not mean the sensor samples vibration once every 15 minutes. The sensor may acquire a short high-rate signal and transmit a summary, or retain a waveform under specified conditions. Request both acquisition and communication settings. Specify which setting can be changed, by whom, and how a change affects battery use, storage and cost.

As a hypothetical example, a shaft rotating at 60 rpm completes one revolution per second. A 2-second acquisition covers about two revolutions; a 20-second acquisition covers about twenty. This explains why duration matters when a specialist wants to examine repeated behaviour. It is not a recommended setting for every gearbox: suitable duration, bandwidth and processing depend on the mechanism and diagnostic method.

Mounting can determine whether the comparison is useful

Describe the bearing housing, measurement direction, surface and available access. A repeatable mounting path is important when comparing observations before and after maintenance. Include clearance for moving parts, guarding and hot surfaces. The person approving access must be able to explain how the sensor is installed and serviced safely during the appropriate machine state.

Record the installed position with a labelled photograph and machine identity. If a sensor is moved during a repair, the next reading needs that context. A changed trend can arise from a new mounting position as well as a changed machine. Retain relevant configuration and maintenance events with the signal rather than relying on memory.

What determines the price of vibration monitoring?

Count the required measurement positions, not only the number of machines. A motor and gearbox train can have several mechanically distinct points. The price also changes with sensor acquisition capability, mounting, access, power, communications, export rights and specialist review. Ask whether equipment is purchased, supplied as part of a service or owned by another contractor.

Separate the initial survey and installation from recurring connectivity, platform access, batteries, reference checks and interpretation. An inexpensive sensor-only offer is not directly comparable with a package that includes installation and a machinery specialist. Equally, paying for interpretation is useful only if the operating records and maintenance team are available to act on the findings.

No independently verified retail range is assigned to these different packages here. Use dated quotations for the same measurement and interpretation scope. For the investment case, calculate the cost of unplanned downtime using the site's actual lost contribution and recovery options, without treating all lost production value as recoverable savings.

Start with a machine that has a clear owner

Choose an asset whose duty can be described and whose maintenance team can investigate an unusual observation. Ask that team to provide speed, load, recent work and known fault history. A first baseline should cover representative operating states so that routine duty changes are not mistaken for machine deterioration.

Agree what the pilot is demonstrating: measurement quality, data transport, a repeatable baseline, an alert workflow or a separately evidenced diagnostic claim. Success in one category does not establish all the others. The sampling specification guide and alert-to-work-order guide help connect the technical purchase to maintenance action.

Choose the matching equipment project

Pump monitoring needs hydraulic and operating context. Fan monitoring should preserve speed, loading and cleaning history. Motor and gearbox monitoring needs attention to shaft speed and acquisition. Compressor monitoring separates loaded and unloaded operation. Mine asset monitoring adds access, criticality and local maintenance requirements.

These are different project tasks even where they share a gateway or reporting platform. Ask for a proposal that names the actual asset, selected positions and people responsible for interpretation, rather than a generic device count with an assumed prediction service.

Method background

The US Department of Energy operations and maintenance guide provides background on condition-based maintenance. Equipment-specific criteria and diagnostic claims require the relevant machinery expertise and evidence.

Include the cost of reviewing an alert

Ask who examines an unusual observation before work is issued, what operating information they receive and whether that review is included in the service. A plant with its own machinery specialist may need a different package from a site seeking external interpretation. During the trial, follow one agreed test event through notification, review and the maintenance record.

Record the action taken and the reason; a notification count alone does not describe useful maintenance work. Include the cost of collecting missing speed or load information if it is necessary for that review. This makes the comparison between sensor-only and managed packages explicit and gives procurement a deliverable beyond the number of installed devices.

Frequently asked questions