NORMAL OPERATION
The UV254SD can measure and store three different kinds of values:
• The intensity (in mW/cm
2
) of UVA light
• The intensity (in mW/cm
2
) of UVC light
• Temperature (in ºF or ºC), as sensed by a Type K or Type J thermocouple
Pressing and holding the FUNC./HOLD/NEXT button will bring up, in order, three blank
five-digit displays above the terms “A” (for UVA light), “C” (for UVC light) and “tP” (for
temperature). Each display also automatically shows the correct unit for the parameter.
1. To select the measurement mode
, release the FUNC./HOLD/NEXT button when the
desired parameter appears. This becomes the meter’s default measurement mode until
you change it.
Whenever the UV254SD is in measurement mode, you can turn off the backlight (which is
on by default) by briefly pressing (but not holding) the POWER/ESC button. To reactivate the
backlight, briefly press the button again.
Whenever the meter is in measurement mode, you also can check the current date and
time by briefly pressing the SET
▼
button. Doing so causes both values to appear briefly
at the lower left of the display.
2. To measure the intensity of UVA light
, seat the UVA probe (with its cap on) in the
socket at the top of the UV254SD (callout 1-7) and use the FUNC.HOLD/NEXT button to
select UVA measurement mode. If the display shows a value other than zero, press the
LOGGER
▲
button (which has the word “Zero” stenciled above it) and hold it for at least
three seconds until you hear a beep. Then remove the cap from the probe.
Holding the probe by its handle, point the sensor at its end directly at the light source. The
display will read out the intensity of the source’s UVA light component in units of mW/cm
2
.
3. To measure the intensity of UVC light
, seat the UVC probe (with its cap on) in the
socket at the top of the UV254SD and use the FUNC.HOLD/NEXT button to select UVC
measurement mode. If the display shows a value other than zero, press the LOGGER
▲
button (which has the word “Zero” stenciled above it) and hold it for at least three
seconds until you hear a beep. Then remove the cap from the probe.
Holding the probe by its handle, point the sensor at its end directly at the light source. The
display will read out the intensity of the source’s UVC light component in units of mW/cm
2
.
4. To measure temperature
, first make sure neither the UVA nor the UVC probe is plugged
into the instrument. Then use the FUNC.HOLD/NEXT button to select temperature
measurement mode.
Obtain a Type K or Type J thermocouple and seat it in the socket (callout 1-8) on the top of
the UV254SD. The display will read out the sensed temperature in degrees F or C,
(depending on the setting chosen during setup), along with the type of thermocouple it is
configured for.
To change the unit of measurement, press the SET
▼
button to enter setup mode and
perform Step 8 of the setup procedure. To configure the meter for use with a Type J
thermocouple (Type K is the default), press the SET
▼
button to enter setup mode and
perform Step 7 of the setup procedure.
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