Extech Instruments 445815 User Manual

User Manual
Model 445815 Humidity Alert II
Humidity Indicator with Dew Point and Programmable Hi/Lo %RH Alarms
445815-en-US_V3.5 8/23
Introduction
Congratulations on your purchase of Extech’s Humidity Alert II Remote
Probe Hygro-Thermometer. Humidity alarms warn when the %RH
exceeds a pre-set HI or LO limit. The remote probe conveniently mounts
on the meter or extends for measurements in ducts or remote locations.
It also features Humidity and Temperature adjustments. The unit can be
wall-mounted or placed on a flat surface using the fold-out stand. This
professional meter, with proper care, will provide years of safe reliable
service.
Meter Description
1. Temperature-Humidity Sensor
2. %RH Display
3. Dew Point Display
4. Temperature Display
5. %RH LED alarm
6. Max/Min push button
7. Reset push button
8. Sensor cable storage
9. Tilt Stand
10. Humidity calibration adjust
11. Temperature units switch (ºF/ºC)
12. Temperature calibration adjust
13. Wall hanger
14. Battery compartment
15. Audible Alarm ON/Off switch
Cautions
• Do not leave batteries and packing material lying around unattended;
they can be dangerous for children if they use them as toys
• In case the device is going to be unused for an extended period of
time, remove the batteries to prevent them from training
• Expired or damaged batteries can cause cauterization on contact
with the skin. Always, use suitable hand gloves in such cases
• See that the batteries are not short-circuited. Do not throw batteries
into the fire.
Operation
Preparation for use
Open the battery compartment by pushing the cover on the rear of the
instrument downward as indicated by the arrow. Remove the battery
insulating strip and the protective film cover on the LCD display.
Temperature Units
Select ºF or ºC units using the rear selection switch.
Audible alarm
Select or using the rear selection switch to turn the audible
alarm on or off.
Maximum / Minimum display
1. Press the MAX/MIN button. The highest value measured since the
Reset button was last pressed appears on the display.
2. Press the MAX/MIN button again to display the lowest value
measured since the Reset button was last pressed.
3. Press the MAX/MIN button again to return to normal display
operation.
Resetting (clearing) the MAX/MIN memory
1. Press the MAX/MIN button to enter the MAX/MIN mode.
2. Press and hold the RESET button for 1 second to clear the memory
and start recording new max/min values.
Setting the %RH Alarm Limits.
1. Simultaneously Press and HOLD the MAX/MIN and RESET button
until “HI” and the stored HI %RH limit appears flashing.
2. Press the RESET button to set the Hi %RH limit. Hold the button in
for rapid adjustment.
3. Press the Max/Min button. “LO” and the stored LO %RH limit will
appear flashing
4. Press the RESET button to set the LO %RH limit.
5. Press the Max/Min button to turn on or off the alarm. The alarm
icon will appear in the display when the alarm is active.
6. Press and hold the RESET button to save the settings and exit the
mode.
Alert
If %RH exceeds the HI limit or goes below the LO limit the alert will be
activated. The alert consists of two flashing ‘ALERT” icons in the upper
display, a flashing red light (for 60 seconds) and an audible buzzer (for
60 seconds)
Calibration
RH Calibration
1. Insert meter’s sensor into a humidity chamber.
The reference should be 85% RH at 21°C.
2. Check the reading after 1 hour.
3. Adjust the RH calibration pot in ½ turn increments, waiting for the
display to update after each adjustment, until the reading is within
the accuracy specification.
Temperature Calibration
1. Place the sensor in a stabilized environment of approximately 21°C.
2. Check the reading after 1 hour.
3. Adjust the temperature calibration pot in ½ turn increments, waiting
for the display to update after each adjustment, until the reading is
within the accuracy specification.
Battery Replacement
Open the battery compartment by sliding the battery cover on the rear of
the instrument downward as indicated by the arrow. Replace the 1.5V
‘AAA’ batteries and replace the cover.
Specifications
Range
Accuracy
Temperature
14 to 140
o
F
-10 to 60
o
C
+ 1.8
o
F within 14
o
F to 122
o
F
+ 1.0
o
C within -10
o
C to 50
o
C
Humidity
10% to 99%
+ 4% RH within 25% to 85% RH and 0
to 50
o
C or 32 to 122
o
F
Dew Point
-32.8 to 140
o
F
-36 to 60
o
C
+/-3.6
o
F @ 68
o
F
+/-2
o
C. @ 20
o
C
Battery
(2) 1.5V 'AAA' cell
Weight
6 oz (169g)
Dimensions
Display: 4.3x3.9x0.8” (109x99x20mm)
Probe: 0.57” (14.4mm) Dia.: 1.67”(42.4mm) L
Cable length 18” (457mm)

Extech Instruments 445815 Specifications

General

Brand	Extech Instruments
Model	445815
Category	Measuring Instruments
Language	English