Testboy TV 325 Mode D'emploi page 24

Functions
Size of measuring surface - distant-to-spot ratios (D/S)
In order to get accurate measuring results, the object to be measured must be larger than the
measuring surface of the infrared thermometer. The detected temperature is then the average
temperature of the measured surface area. The smaller the object is the shorter the distance to
the infrared thermometer should be. The exact size of the measurement area can be seen in the
following diagram. This is also printed on the outside of the instrument.
For exact measurements, the object to be measured should be at least twice the
size of the measured surface area!
°C/°F toggle
Using the "down key", you can change the temperature display between °C and °F.
Contact measurement with a type-K probe
In addition to the non-contact infrared measurement feature, the Testboy
with a type-K probe for performing contact measurements. In order to make contact
measurements, connect a standard commercially-available type-K probe with a standardized
mini-plug into the appropriate socket on the instrument.
Use the MODE key to select the "PRB" function. The temperature value from the type-K probe
will then be shown in the lower display row.
Alarm function
Use the MODE key to select the value that you wish to set for the alarm value. "HAL" for the
upper alarm value (high alarm) or "LAL" for the lower alarm value (low alarm). Use the two arrow
keys to set the required value. The instrument issues an optical and audible alarm if a non-
contact measurement falls below or above these alarm values. The display then shows the alarm
symbols "Hi" or "Low".
The emissivity is a value that is used to describe a material's energy radiation characteristic.
The higher this value, the higher the ability of the material is to send out radiation. Many organic
materials and surfaces have emissivity of approximately 0.95. Attached is a list of the emissivity
values of several materials. Metallic surfaces or shiny materials have low emissivity. Therefore,
the Testboy TV 325 is fitted with an emissivity-setting feature. Despite this adjustable emissivity
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TV 325 is equipped
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Testboy TV 325