Instrom Limited is an independent security consultancy set-up in 1998 to provide a range of impartial security consultancy services to commerce, industry and the public sector.
Glossary Of Terms (A-C) - CCTV ACAlternating CurrentACCESS CONTROL SYSTEMElectronic system used to allow, restrict and track the movement of people through entry/exit points in a site. This is achieved through the use of electronic individual codes, keys or cards etc, to release a locking mechanism.... Similar Editorial : Glossary Of Terms by Instrom Ltd. | Source : Gadget Review
Glossary Of Terms (D - L) - CCTV DARK CURRENTLeakage signal from a CCD sensor in the absence of incident light.DARK NOISENoise caused by the random (quantum) nature of the dark current.DECIBEL (DB)A logarithmic ratio between two electrical signals or values. Usually refers to power, b... Similar Editorial : Glossary Of Terms by Instrom Ltd. | Source : Gadget Review
Glossary Of Terms (M - R) - CCTV MAGNIFICATION RATIOThe ratio between the focal length of a lens and the focal length of a standard angle lens. Indicates the magnification of the image when compared to an image from a standard angle lens.MANUAL IRISType of lens that requires manual focusing.... Similar Editorial : Glossary Of Terms by Instrom Ltd. | Source : Gadget Review
Glossary Of Terms (S - Z) - CCTV S/N RATIOSignal-to-Noise ratio is calculated with the logarithm of the normal signal and the noise RMS value.SCENE ILLUMINATIONThe average light level incident upon a protected area. Normally measured for the visible spectrum with a light meter having a spectral respons... Similar Editorial : Computer Glossary by Crestech. | Source : Gadget Review
