Corrosion and wear in External PTZ dome ‘window-wiper’ mechanisms can be a continual maintenance headache for installers. If domes are located in hostile, hazardous or harsh environments, the problems are exacerbated.
The wiper used in Redvision’s X-SERIES™ dome / ball PTZs uses a simple and highly effective linkage-free, sprung steel mechanism with a silicon rubber wiper blade. Not only does it have very few moving parts to immediately reduce wear issues, but it also keeps a uniform pressure between the wiper blade and optical surface to remove water consistently.
“Fewer parts means greater reliability,” explains Paul Hucker, Managing Director of UK based manufacturer, Redvision. “Wear and corrosion can cause breakage and seizing in external dome wiper mechanisms. In coastal locations, for example, lubricants can be stripped off by sea-side weather conditions, leaving parts unprotected and exposed to the elements and likely to fail.”
Redvision’s simple wiper design is only possible because the X-SERIES™ has a flat glass window in front of the camera module. The “bubble”, or hemispherical plastic cover used in many other dome designs, requires a more complex wiper mechanism because of its shape, which is more susceptible to wear. The flat window is made from scratch-resistant, optically-correct glass, not plastic like many domes, so damage to the optical surfaces from the wiper blade itself is significantly less likely.
Paul explains why a wiper is essential in PTZ domes. “External domes must be capable of removing rain drops from optical surfaces as dome camera modules are prone to focusing on the water droplets on the optical surface, not the camera scene. Even if this does not happen, the camera’s view is obscured and its image quality reduced by surface water. As the optical zoom in PTZ dome cameras increases, (such as the 28x optical zoom used in the X-SERIES™), they are even more likely to focus on the optical surface.”
Redvision has included wiper activation on a switch and as a defined preset. The preset option makes the wiper functionality available to CCTV systems that do not have a wiper on/off command. The wiper will also time out, so does not continue running without an operator realising.
The simple design is easy to maintain and Redvision offers a replacement wiper blade pack for installers needing to replace worn blades.
Contact Redvision on 01420 448 448 or visit www.redvisioncctv.com for more information.