There are various circumstances where you may want to measure the vibration of an object that is out of reach. It may be too dangerous, too costly or too time-consuming to reach, but there may still be an answer. Vibrometry is a non-contact form of vibration measurement, and Polytec vibrometers can measure objects up to 300 metres away.
Here are some of the applications that Polytec instruments have been used for:
Bridges
Using accelerometers to measure a bridge can be expensive. It requires multiple people working at height and using equipment such as scaffolding to place and maintain them.
While all bridges carrying vehicles should be monitored to check the structural integrity and to spot any weaknesses before they become a danger, continuous monitoring is only necessary for a minority of them.
Vibrometers can be used to check 100s of points in a short timescale from a distance. This means that organisations responsible for maintaining bridges can have a regular monitoring schedule and fix any weaknesses before they become an issue. They don’t have to put themselves in harm’s way to check the bridge, and they may well be able to keep traffic moving at the same time.
Overhead gantries
Much like bridges, gantries over roads and railways need to be monitored to check their structural integrity and spot any early indications of damage. The last thing maintenance personnel need is to stop trains or traffic to measure vibrations. Being able to measure from a safe distance makes vibrometry ideal for measuring overhead gantries.
Power lines and Pylons
In this modern world, we are reliant on having a reliable 24/7 electricity supply. With powerlines and the pylons that carry them open to the elements, it is important to monitor them. High winds, in particular, can cause problems such as aeolian vibrations that can lead to wear and tear, such as conductor fatigue and damage to hardware like dampers and spacers.
Accelerometers are not appropriate as they cannot be attached to the powerlines themselves, and the electromagnetic field near powerlines can impact the readings from accelerometers. Even if checks were only done while electricity was not running through the lines, it would involve people working at height and would not represent the behaviour while in operation.
That is why vibrometry is a great technology for this application. It can be safely used from the ground and while the powerlines are in operation.
Through glass
There are various applications where the only safe way to measure an object's vibration is through glass. This may be due to extreme temperatures, high pressures, or anything else that causes danger. These include engine testing in aerospace, climatic chambers in academic research, or a vacuum for testing satellites.
As light can travel through glass, laser-based technology can be used from the other side of the glass. Polytec instruments and their software can be calibrated to account for the bending of light and change in speed through glass.
Historical ceilings and lighting
Many historical buildings, for example, stately homes and theatres, have ornate plasterwork ceilings and delicate lighting, such as chandeliers that need to be preserved. Any issues need to be identified as early as possible so that any repair and restoration can take place before the damage spreads.
Historical theatres have age and gravity to worry about, but stately homes open to the public have the added issue that 100s of people regularly walk on floors above these ceilings that they were never designed to handle.
By using vibrometry to check the vibrations of ceilings and lighting, not only are problems discovered before they are visible to the naked eye but vibrometers can be used from the floor, meaning that scaffolding only needs to be erected and the space closed if repairs are needed.
Wells
While most of us in the UK have a public water supply from a water company, approximately 1% of the population has a private water supply, which is often taken from a well. However, most wells are used in the agriculture industry for both plants and livestock.
Most modern wells use a pumping system that needs to be maintained. These wells can be very deep, making them difficult to access.
Another issue is the structure of the wells themselves. Temperature changes, landslides and even UK earthquakes can damage wells and lead to water contamination.
Vibrometry can be used while pumps are in operation to check the vibration of machinery and the well structure at the bottom of the well.
Restricted areas
Sometimes, you want to do spot checks on machinery and in automated factories that are not easy to reach safely while in operation. Easily portable single-point vibrometers such as the Polytec VibroGo® are ideal for this. For example, for maintenance staff or contractors who are responsible for multiple sites or large sites with multiple check points.
If you have an application that is out of reach, contact our UK team on 02475 267 020 or at info@polytec-ltd.co.uk to find out if vibrometry is the answer.
Find out more about Polytec vibrometers here: www.polytec.com/uk/vibrometry