General Tools and Instruments IRT730K - Manual (Page 8)

To move from one display mode to the
next in the sequence, briefly press
(but do not hold) the MODE button.
ADJUSTING EMISSIVITY AND SETTING TEMPERATURE ALARMS
The IRT730K has three parameters that you can set anywhere over a predefined range:
1. Emissivity (
ε)—the ability of an object to reflect or absorb IR radiation (energy)—can be
assigned any value between 0.10 and 1.00 in steps of 0.01. The default (factory setting)
of
ε is 0.95. Because the IRT730K measures the amount of infrared energy emitted by a
surface, its measurements are most accurate when they take into account the
characteristic emissivity of the target material.
A perfectly absorbent surface (called a black body) has an emissivity of 1; it absorbs
100% of the thermal energy hitting it. An object with an emissivity of 0.8 absorbs 80% of
IR energy and reflects 20% of it. All emissivity values fall between 0 and 1; as a rule, the
shinier the surface, the lower its emissivity.
To maximize the accuracy of IRT730K measurements, you should enter the actual
emissivity of the target surface (see Appendix II) using the instrument’s three buttons and
the procedure below. Compensating for emissivity will particularly improve the accuracy
of measurements of surfaces with emissivities nearer to zero than to the
default IRT730K setting of 0.95.
2. High Temperature Alarm (HAL). As mentioned earlier, the HAL setpoint can be set to any
integral temperature value from -58° to 1472°F (-50° to 800°C)—the operating range of
the IRT730K.
3. Low Temperature Alarm (LAL). The LAL setpoint also can be set to any integral
temperature value from -58° to 1472°F (-50° to 800°C)—the operating range of the
instrument.
The presetting of the high and low temperature alarms to the high and low limits of the
instrument’s measurement range is a convenience. If you never change the value of HAL or
LAL (because you choose not to use temperature alarms) from its default value, you will never
be bothered by an alarm inadvertently sounding because you forgot to reset an alarm
threshold. Neither alarm can be disarmed.
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