Fluke Ti20 user manual Level

Models: Ti20

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Level

Ti20

Users Manual

Level

Level is the median point of a given temperature scale. For example, if the unit is currently in Automatic mode, and there is a given thermal scene with MIN and MAX temperature limits, the moment you switch the unit to Manual mode, the Level value is set by the unit according to the following formula:

Max Span + Min Span

Level =

Micron (or µm)

10-6meters (m), or 0.000001 m.

Minimum spot size

2

dag129f.eps

The smallest spot an instrument can accurately measure.

NETD

Noise Equivalent Temperature Difference. Peak to peak system electrical noise normally measured at the output (display or analog) expressed in °F or °C.

NIST Traceability

Calibration in accordance with and against standards traceable to NIST (National Institute of Standards and Technology, USA). Traceability to NIST is a means of ensuring that reference standards remain valid and their calibration remains current.

Non-Gray Body

A radiating object that is partly transparent to infrared (transmits infrared energy at certain wavelengths); also called Colored Bodies. Glass and plastic films are examples of non-gray bodies.

Optical Pyrometer

A system that, by comparing a source whose temperature is to be measured to a standardized source of illumination (usually com-pared to the human eye), determines the temperature of the former source.

Optical Resolution

The distance to size ratio (D:S) of the IR measurement spot, where the distance is usually defined at the focus distance, and the size is defined by the diameter of the IR energy spot at the focus (typically at the 90% IR energy spot diameter). Optical resolution may also be specified for the far field by using values of far field distance and spot size.

Pyroelectric Detector

Infrared detector that behaves as a current source with an output proportional to the rate of change of the incident IR energy.

Radiation Thermometer

A device that calculates an object’s temperature (given a known emissivity) from measurement of either visible or infrared radiation from that object.

Reflectance

The ratio of the radiant energy reflected off a surface to that incident on the surface; for a gray body this is equal to unity minus emittance; for a perfect mirror this approaches unity; and for a blackbody the reflectance is zero.

A-4

Page 54
Image 54
Fluke Ti20 user manual Level