Choosing the right bearings for CCTV applications
2 November 2018
Britain is the most watched nation in the world — home to just one per cent of the world’s population, but 20 per cent of its CCTV. To support this developing infrastructure, CCTV bearing supplier SMB Bearings, helped the market leader of network cameras, with a common CCTV camera issue — bearing outgassing.
The world's first network camera was manufacturered back in 1996. It revolutionised the industry, transforming video surveillance from analogue to digital. However, an effective camera network relies fundamentally on the visibility and precision of the individual cameras, and the expert engineering that goes into designing them.
If a network of cameras cannot capture clear images, the entire installation loses its value. That said, ensuring visibility is not entirely reliant on the quality of the lens and the positioning of the camera itself. Choosing the correct internal components, such as bearings, plays a huge part in this.
Choosing the right bearings for CCTV applications addresses a two-part problem. Firstly, is the need for smooth, predictable and accurate camera movements, in perfect calibration with the instructions from the operator or sensor software. This is dependent on using bearings with the right frictional coefficient, based on grease level, bearing material and lubrication type.
The second problem that needs to be addressed is lubrication outgassing. Heat is generated within the bearings during operation causing the lubrication inside the bearing to warm up. A small amount of this lubrication can escape from the bearing in a gaseous state over time, meaning oils and greases that were once confined to the bearing, enter the external environment. This isn't an issue for many applications, but in CCTV, cleanroom or vacuum applications, it can have disastrous consequences.
Outgassing, in the application of CCTV cameras, has detrimental effects on image quality. The escaped gas causes condensation on the camera lens meaning effective video footage isn't recorded — often, the image is completely obscured.
Imagine a CCTV manufacturer found that, when in use, its cameras failed to capture the clear, high-quality footage. Not only would this require an investigation into the cause of the problem, but could result in costly reengineering of the product itself.
In this instance, the manufacturer may have discovered that the lubricant in the bearings dispelled oil vapour when in operation, resulting in substandard and unclear footage.
But, how can a manufacturer resolve this issue? Rather than trying to fix the symptom, manufacturers must address the root cause — the bearings and their lubrication.
To avoid outgassing, the manufacturer should choose thin section ball bearings, pre-lubricated with low outgassing bearing grease, in accordance with the size specifications. The thin section bearings facilitate precise and accurate camera movements. When equipped with low outgassing perfluorinated grease, the combination prevents the fogging caused by outgassing.
For engineers that already use precision bearings, it may be that just the lubrication that needs addressing. In cases like this, buying entirely new bearings isn’t necessary. Relubrication services are available, to clean out existing lubrication, and refill the bearings with lubrication that is fit for purpose. SMB Bearings has in-house relubrication facilities, and even carry out the service for small batches.
Britain is a nation under surveillance, with one CCTV camera per eleven residents. CCTV cameras are often designed to be used 24 hours a day, seven days a week, and producing unclear images simply is not an option if the priority is to keep the nation safe. To discuss your own design specification or CCTV camera repair challenges, e-mail firstname.lastname@example.org.
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