CCTV Camera/ Device Installer

  Home  Technical  CCTV Camera/ Device Installer


“CCTV Camera/ Device Installer related Frequently Asked Questions by expert members with professional career as CCTV Camera/ Device Installer. These list of interview questions and answers will help you strengthen your technical skills, prepare for the new job interview and quickly revise your concepts”



45 CCTV Camera/ Device Installer Questions And Answers

22⟩ What is Television Lines (TVL)?

This is a measure of the resolution of a video device. The higher the number, the higher the resolution is. 380 TVL is considered medium resolution. 480 TVL or greater is considered high resolution.

 130 views

23⟩ What is Internal Sync?

Devices with internal sync have an internal crystal to provide sync pulses without needing reference from any external device.

 146 views

24⟩ What is compression?

Digital video pictures can be compressed with a number of techniques. These include: JPEG and JPEG-2000 (for still images), M-JPEG and MPEG (for moving pictures).

 160 views

26⟩ What is Pinhole Lens?

This is a type of lens with a very small aperture. Normally used for covert applications, where it can easily hide behind or within another object.

 132 views

27⟩ What is looping?

Connecting an additional device in parallel with an existing video cable. For example, when driving a video recorder as well as a monitor from the same video signal.

 124 views

28⟩ What is Dwell Time Programming?

The length of time a switcher or CCTV multiplexer displays one camera before sequencing to the next. Multiplexers with dwell time programming capability allow you control this length of time.

 137 views

29⟩ What is alarm Input?

Some DVRs and security cameras have alarm inputs, which can accept input from a sensor device such as a door contact or a passive infra-red motion detection which trigger the camera or DVR to take some action such as to begin recording.

 158 views

31⟩ What is RS-485?

RS485, also referred to as EIA-485 is a communications standard for serial communication between devices. When talking about surveillance systems, RS-485 is typically used as the protocal to allow computers and remote controllers to control the activity of cameras such as pan, tilt, rotate, and zoom operations. RS485 is an updated version of the original serial protocol, RS-232.

 163 views

32⟩ What is PAL?

PAL is an abbreviation for Phase Alternating Line. This is the television display standard that is used mainly in Europe, China, Malaysia, Australia, New Zealand, the Middle East, parts of Africa, and other parts of the world. PAL uses 625 lines per frame and a frame rate of 25 frames per second.

 150 views

33⟩ What is IP Waterproof Rating?

IP waterproof ratings are a BSi standard measurement for how waterproof something is. Many security cameras or camera housings are designed for outdoor use need to be waterproof. The IP rating number has two digits, and optional letters after them. E.G IP66 and IP68. The first number defines the protection against ingress of foreign objects. 0 is the lowest rating and means non-protected. 6 is the highest rating and means dust tight and protects against access with a wire. The second number defines the level of protection against ingress of water. 0 is the lowest rating means non-protected. 8 is the higest rating and means protects against continuous immersion in water.

 128 views

34⟩ What is Co-Axial Cable?

A type of cable typically used in cctv installations that has a central conductor, surrounded by a shield sharing the same axis. The shield can be made from a variety of materials including, braided copper, or lapped foil. There are various standards for specific types of co-axial cable. The cable used for normal CCTV installations is called RG59.

 134 views

35⟩ What is back Light Compensation?

This is a feature of security cameras that automatically adjusts the image to compensate for bright light to give more detail on the darker areas of the image. For example, use is to focus on the detail of a face of a person that has the sunlight shining from behind.

 140 views

36⟩ What is router?

A device that forwards data packets along networks. Typically when referred to in CCTV installations, a router is used to connect a surveillance DVR and a computer to a single internet connection. A router can also be used to connect multiple IP based security cameras to a single internet connection.

 138 views

37⟩ What is aperature?

The opening of the CCTV lens. The size of which is controlled by the iris and is measured in F numbers. Generally, the lower the F number, the larger the aperture is and consequently more light can pass through the lens.

 124 views

38⟩ What is Composite Video?

The encoded output of a surveillance camera whereby the red, green, and blue video signals are combined with the synchronizing, blanking, and color burst signals and are transmitted simultaneously down one cable.

 148 views

39⟩ What is C Mount Lens & CS Mount Lens?

There are two main types of lenses used in security cameras. The C mount lens has a flange back distance of 17.5mm. The CS mount lens has a flange back distance of 12.5mm. C mount lenses therefore have a longer focal distance. CS mount became widely used, because it its more practical for many of today's more compact cameras. Lenses are often supplied with a 5mm spacer ring (sometimes called a C ring) that allows a C mount lens to be used on a CS camera. Most modern security cameras are CS.

 130 views

40⟩ What is auto Iris?

Security cameras with auto iris, have the ability to compensate for large variations in light levels. This is useful for security cameras that need to adjust for changes from bright sunlight to darkness or night. Auto iris circuitry is normally linked to a motorized drive that opens and shuts the iris on the camera lens. Closing a physical iris is a much better way to protect a camera from being damaged by bright sunlight then simply using electronics to reduce the signal strength.

 132 views