Glossary

Crimping

Is a process of connecting a cable to a connector without screwing or soldering using a special tool. In crimping a BNC connector, the cen- tre pin of the connector is uniformly pressed against the cable core. To ensure a proper connection, a good crimping tool is needed.

Cross Talk

Is the noise generated by the interference between adjacent (in terms of signal frequency) video, audio or data channels in a multi- plexed signal.

CS-Mount

Is a lens mount with 12.5 mm back flange. The back flange is the dis- tance between the lens mounting surface and the CCD chip. Cameras with CS-mount need a special adapter ring to be used with C- mounted lenses (supplied with every camera).

DC

Direct current

Decibels

Is a logarithmic ratio used to compare characteristics of electrical sig- nals.

De-multiplexing

Is the process of separating the different video, audio or data chan- nels which were multiplexed at the source.

Depth of Field

Is the distance between the nearest and furthermost points of the scene which appear in sharp focus. It is dictated by the F-stop and focal length of the lens.

Dielectric

Is a material which insulates the solid centre core of a coaxial cable from the screen. The thickness of the dielectric affects the impedance of the cable.

Dome

Is a type of camera kit, inside a housing made of smoked or tinted plastic. It is excellent for discreet surveillance and is supplied with inbuilt pan tilt heads and zoom lens mechanisms.

DSP Chip Digital Signal Processing Chip

Is a solid state device which converts an analogue video signal into a digital video signal. It is used in digital cameras and also in computers to digitise video images.

Duplex

Is a system which can handle simultaneously two channels of video, audio or data signals.

Dwell Time

Is a feature in a switcher. It is the time period a picture from a given camera remains on the monitor before being replaced by a picture from the next camera. Switchers may have fixed or programmable dwell times.

EASS Electronic Surveillance System

It is used in retail shops to electronically tag the article merchandise to prevent shop thefts. A CCTV system can be interfaced with an EASS system so that the appropriate camera is switched on when an of- fence occurs.

EIA

Is a scanning method specified by the Electrical Industry Association. RS-170 is the standard for monochrome and RS-170A is the standard for colour.

Electrical Filter

Is a type of electrical circuitry designed to limit transmission of cer- tain frequencies.

Electron Beam

Is a concentrated flow of electrons in a nominated direction.

Electronic Shutter Speed

See Shutter Speed.

Shutter Speed

Is the speed at which the charge is read out from the CCD chip. The factory setting is 1/50 sec (PAL) or 1/60 sec (NTSC) and can be increased up to 1/100,000 sec depending upon the camera brand. It can be changed by using dip switches or in some cases by the inbuilt menu in the camera.

EMI Electro Magnetic Interference

Is interference which is usually caused by any electrical equipment radiating electro magnetic frequencies.

Ergonomics

Is the study of man, machine and the environment to achieve maxi- mum efficiency.

Event Recorder

Is a type of recorder that is normally maintained in pause mode and starts recording only when activated by an alarm.

Extruded Aluminium

 

Is aluminium processed through a die and shaped for use to construct

 

housings for CCTV applications.

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Extruded Plastic

Is a process in which smoked or tinted plastic is processed and shaped to construct dome housings.

F-stop

Is the ratio between the focal length of the lens and the effective diameter of the iris opening. It indicates the light gathering ability of the lens.

Fence Protection System

Is a type of sensor installed on or around the perimeter fence in a site to detect any intrusion. There are many types of fence protection sys- tems available. In CCTV it can be interfaced with a switcher or similair piece of equipment to switch a nominated camera for extended view- ing.

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Siemens TFT, CRT manual Eia

CRT, TFT specifications

Siemens, a prominent name in electronics and engineering, has made significant contributions to display technology, particularly in the realms of Thin Film Transistor (TFT) and Cathode Ray Tube (CRT) displays. These technologies have paved the way for advancements in visual media, ranging from television sets to computer monitors.

TFT display technology, a type of LCD (Liquid Crystal Display), employs thin film transistors to produce brighter and more vibrant images. One of the main features of TFT displays is their ability to deliver high resolution and excellent color reproduction, making them ideal for various applications such as smartphones, tablets, and laptops. TFT screens utilize an active matrix approach, which allows each pixel to be controlled individually. This method results in faster response times and improved image quality, with less motion blur, compared to older passive matrix displays.

One of the key characteristics of TFT technology is its versatility in different settings. It supports a wide range of viewing angles, which enhances the user experience whether one is viewing the display head-on or at an angle. Additionally, TFT displays are known for their thin profile and lightweight design, contributing to the overall portability of devices that incorporate them.

On the other hand, CRT technology, which was once the standard for televisions and computer monitors, uses electron beams and phosphorescent screens to produce images. One of the defining features of CRTs is their ability to display deep blacks and a wide color gamut. CRT technology can achieve high refresh rates, reducing flicker and improving the quality of fast-paced visuals. However, CRTs tend to be bulkier and heavier than modern display technologies like TFT.

Despite the evolution towards flat-panel displays, CRT technology is still appreciated for its natural color and motion portrayal. Siemens has leveraged these characteristics to produce quality CRT monitors that were favored in professional settings, including graphic design and medical imaging, where color accuracy is paramount.

In summary, Siemens has played a vital role in advancing both TFT and CRT technologies. TFT displays are recognized for their high resolution, fast response times, and design versatility, while CRTs are celebrated for their rich color and depth. As technology continues to advance, the legacy of these display types remains influential in shaping modern electronic devices.