The High Temperature Alarm is activated when the temperature measured by the IRT is higher
than the
HAL
setpoint. The Low Temperature Alarm is activated when the temperature
measured by the IRT is lower than the
LAL
setpoint. In each case, the OS730K responds by
sounding a second chirp (following the usual first chirp to indicate that a measurement was
made and stored) and flashing an icon on the bottom line of the LCD (Fig. 2, Callouts 13 and
14). The second chirp is the only audible indication that a temperature alarm has been
activated.
To change the unit’s emissivity setting and either alarm threshold, press and hold the MODE
button
with the instrument powered on and operating in any mode.
Whatever the operating mode, pressing and holding the
MODE
button will cause the emissivity
icon
ε
(Fig. 2, Callout 2) on the top line of the LCD to begin flashing. You now have 30 seconds
to change the emissivity value before the APO function activates. You can change
ε
in 0.01
steps by pressing either the
°C/°F
button to decrease the value or the
/
button to
increase the value. To move up or down quickly, press and hold either button.
With
ε
flashing, pressing the
MODE
button briefly saves the currently displayed value (whether
or not you have adjusted it) and changes the adjustment target to
HAL
. Pressing the
MODE
button causes
HAL
to begin flashing on the bottom left of the LCD. Once
HAL
begins flashing,
you have 30 seconds to adjust its value up or down to any temperature within the unit’s
measurement range. Press the
°C/°F
button to decrease the value or the
/
button to
increase it. To move up or down quickly, press and hold the corresponding button.
Pressing the
MODE
button briefly with
HAL
flashing saves the currently displayed value and
changes the adjustment target to
LAL
. Pressing the
MODE
button causes
LAL
to begin flashing
on the bottom right of the LCD. Once
LAL
begins to flash, you have 30 seconds to adjust its
value up or down to any temperature within the unit’s measurement range. As before, press
the
°C/°F
button to decrease the value or the
/
button to increase it. To move up or down
quickly, press and hold the corresponding button.
Pressing the
MODE
button with
LAL
flashing returns the three-step sequence to its starting
point—with
ε
flashing on the top line. The figure below shows the sequence in graphic form.
Be aware that, unlike values shown on the
primary and secondary readouts (all of which
have 0.1° resolution),
LAL
and
HAL
only have
1° resolution. In other words, do not mistake
the default value of
HAL
(1472°F) for 147.2°F.
RECALLING STORED READINGS
To recall the measurements made and automatically saved by the IRT730K during operation in
REC
mode:
1. Power on the unit by squeezing the measurement trigger.
2. Release the trigger to exit
SCAN
mode. Doing so automatically stores the current IRT
measurement in memory. For the purpose of illustrating how stored measurements are
numerically tagged, assume that this reading is given the memory tag
83
.
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