User's Guide
EasyView Digital Hygro-Thermometer
Datalogger
Model EA25
Introduction
Congratulations on your purchase of the Extech EA25 EasyView Digital Hygro-Thermometer
Datalogger. This device measures and records Humidity, Temperature, Dew Point, and Wet Bulb
data in real-time. Careful use of this meter will provide years of reliable service.
Specifications
Function
Range and Resolution
Accuracy
Humidity
10.0 to 95.0% RH
±3% RH (at 25 C, 30 to 95% RH )
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±5% RH (at 25 C, 10 to 30% RH )
Temperature*
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-4 to 140 F (-20 to 60 C)
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±1.8 F (±1 C)
Display
Multifunction LCD with bargraph and status indicators
Sensor Type
Humidity: capacitance sensor; Temperature: thermistor
Response Time
Humidity: 45% to 95% < 1 min; 95% to 45% < 3 min.
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Temperature: Approx. 2 seconds for a 10 C change
Reading Rate
2 readings per second
RS-232 PC Interface
Optical connection with supplied interface cable. Software compatible
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with Windows XP, Vista and Windows 7 systems
Datalogger storage
Stores 99 sets of data in manual mode (15,000 in auto mode)
Sampling Intervals
3 to 255 seconds (1 to 86,400 sec. using supplied software)
Operating Conditions
32 to 140 F (0 to 60 C); < 95% RH non-condensing
Storage Conditions
14 to 140 F (-10 to 60 C); <70% RH non-condensing
Power Supply
6 x 1.5V ‘AAA’ batteries
Auto power off
After 30 minutes of inactivity
Battery Life
Approx. 200 hours
Dimensions / Weight
5.9 x 2.8 x 1.4” (150 x 72 x 35mm); 8.3 oz. (235g)
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Meter Description
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Humidity/Temperature Probe
Multifunction LCD with bargraph
and status indicators
Power ON/OFF button
MX/MN button
DATA HOLD button
Humidity / Temperature select
button
SET button
Units (C/F) select button
MEM (memory) button
ENTER button
READ button
DEW POINT temperature select
& left arrow button
UP/DOWN programming keys
WET BULB temperature select &
right arrow button
RS-232 optical jack
The battery compartment is
located on the rear of the instrument
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Operation
Turn Power ON or OFF
1. Press the
button to turn the meter on or off. The meter will perform a short self-test when
turned on.
2. The meter automatically turns off after 30 minutes of inactivity unless the MX/MN or Datalogging
modes are active.
Taking Measurements
1. Hold the probe in the air in the area to be tested. Do NOT immerse in liquid.
2. Allow adequate time for readings to stabilize.
3. Read the measurements on the LCD. The bargraph tracks the large digit display.
4. The %RH/TEMP button allows the user to choose whether the temperature or the humidity is
displayed on the large digit display.
Selecting temperature units of measure (C/F)
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Press the C/ F button momentarily to toggle the temperature units.
Maximum and Minimum recording (MX/MN)
NOTE: The Automatic Power OFF feature will be disabled while in the MX/MN mode.
The MX/MN mode allows the user to view only the highest and lowest readings while taking
measurements. (MX stands for maximum and MN for minimum).
1. Press the MX/MN button momentarily to start the elapsed timer and begin recording. The display
will now show only the highest reading (the MX icon will appear).
2. Press the MX/MN button again to view the lowest reading (MN will appear).
3. The SET button allows the user to view the elapsed time for a particular MX or MN reading in
Minutes:Seconds (59mins:59secs max) or Days:Hours (99days:24hours max).
4. To check the highest and lowest Dew Point or Wet Bulb temperatures, use the DEW and the
WET buttons.
5. The following data displays are available in the MX/MN mode:
Maximum and Minimum Humidity with the associated Temperature
Maximum and Minimum Temperature with the associated Humidity
Maximum and Minimum Dew Point temperature with the associated Temperature or Humidity
Maximum and Minimum Wet Bulb temperature with associated standard temperature or
humidity
6. To exit MX/MN mode, press and hold the MX/MN button (the MX/MN icons disappear).
Data Hold
Press the H button momentarily to freeze the displayed reading. The 'H' icon will appear on the
upper left-hand side of the display. Press the H button again to return to normal operation (the 'H'
hold icon will disappear).
DEW POINT and WET BULB Temperature Display
Dew Point and Wet Bulb temperatures are calculated by the meter based on humidity/temperature
measurements. To view the Dew Point or Wet Bulb temperatures, press the DEW or WET button
momentarily. The ‘DEW’ or ‘WET’ display icon will appear on the right side of the LCD and the
temperature will display on the bottom (larger) digits. The upper (smaller) digits will display the
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regular temperature in C or F or the humidity in RH% (use the %RH/TEMP button to toggle
between the two).
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Manual Datalogging
Clearing Previously Stored Data
1. Press the “
” button to turn the meter off.
” button to turn the meter on. When the
2. Press and hold the "MEM" button, then press the “
LCD indicates "CLr", the entire memory has been erased.
Manual Datalogging
1. Press the "MEM" button to store a reading manually. The LCD will display the "M" icon and the
address number. The total memory size for manual recording is 99 sets.
2. When the datalogger memory is full, the LCD will display "Full".
Recalling manually stored data
1. Press the "READ" button to view stored data. The LCD will show the "R" (recall) icon and the
current address number.
2. Use the " " or " " button to select another memory address to view.
3. Press the DEW or WET button to display the Dew Point or the Wet Bulb value.
4. Press " " (enter) to exit this mode.
Automatic Datalogging
NOTE: Before datalogging ensure that previous data has been downloaded otherwise it
will be lost. Up to 15,000 sets of data can be recorded in automatic datalogging mode.
ALL of the following settings must be configured before datalogging:
Real-Time Clock:
Start Time:
Set the time that datalogging will automatically begin
Stop Time:
Set the time that datalogging will automatically stop
Interval Time:
Set the sampling rate (time between logged readings)
Set to the current time in hours, minutes, and seconds
Real-Time Clock Setting
1.
Press the
2.
Press and hold the SET button until two beeps
sound (screen shown at right appears). Note
that if the "" logging icon is already on the
LCD before pressing the SET button, the meter
is already datalogging and cannot be
programmed. To stop logging press " " (enter
button).
3.
Press " " or " " to set the current hour.
4.
Press "" to move to the two flashing digits representing minutes.
5.
Press " " or " " to set the current minutes.
button to power the meter.
6.
Press "" to move to the two flashing digits representing seconds.
7.
Press " " or " " to set the current seconds.
8.
Press " " (enter) to store the time and move to the next screen.
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Datalogging Start-Time (St) Setting
1. The Datalogging start-time screen displays
"St1" and two flashing digits (for the hour).
2. Press " " or " " to set the hour of the day
that datalogging will begin.
3. Press "" to move to the two flashing digits
representing minutes.
4. Press " " or " " to set the desired minute
that datalogging will begin.
5. Press "" to move to the two flashing digits representing the seconds.
6. Press " " or " " to set the desired second that datalogging will begin.
7. Press " " (enter key) to store the datalogging start-time and move to the next screen.
Datalogging Stop-Time (SP) Setting
1. The Datalogging stop-time setting screen shows
"SP1" and the two flashing numbers (for the hour).
2. Press " " or " " to set to the desired hour of
the day that datalogging will end.
3. Press "" to move to the two flashing digits
representing minutes.
4. Press " " or " " to set the desired minute that
datalogging will end.
5. Press "" to move to the two flashing digits representing seconds.
6. Press " " or " " to set the desired second that datalogging will end.
7. Press " " (enter key) to store the datalogging stop-time and move to the next screen.
Datalogging Sampling Interval Setting
1. "INTV" (interval) appears along with the current
interval selection (in seconds).
2. Use the " " or " " buttons to change the
number of seconds (3 to 255). For example, with
003 selected a reading will be automatically recorded every three seconds.
3. Press " " (enter key) to store the sampling interval rate and begin datalogging.
Datalogging Mode
1. In datalogging mode, the LCD will continue to display the "" (logging icon). The LCD will also
flash the "M" icon each time a reading is logged. The meter will shut off when the Stop time is
reached.
2. Use the " " button to display the Start-Time and the " " button to display the Stop-Time.
3. Press "" (enter) to stop datalogging and exit the datalogging mode ("" will disappear).
Note: Readings automatically logged can only be viewed by downloading them to a PC.
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Datalogging Software
The instructions on how to install the datalogging software are printed on the Software CD label.
The software operating manual can be found on the CD.
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Note that the software is compatible with Windows XP, Vista and Windows 7 operating
systems.
Maintenance
Cleaning and storage
1. The meter should be cleaned with a damp cloth and mild detergent when necessary. Do not use
solvents or abrasives.
2. Store the meter in an area with moderate temperature and humidity (refer to the operating and
storage range in the specifications chart earlier in this manual).
Battery Replacement
When the battery power falls low, the ‘BT’ symbol will appear on the LCD. Replace the six 1.5 ‘AAA’
batteries by removing the rear battery compartment screw and accessing the battery compartment.
Check that the polarity (orientation) is correct when placing the batteries in the compartment.
Ensure that the compartment cover is securely fastened when finished.
Calibration and Repair Services
Extech offers complete repair and calibration services for all of the products we sell. For
periodic calibration, NIST certification or repair of this Extech product, call customer service for
details on services available. Extech recommends that calibration be performed on an annual basis
to ensure calibration integrity.
Copyright © 2013 FLIR Systems, Inc. All rights reserved including the right of reproduction in whole or in part in any form ISO‐9001 Certified www.extech.com 7
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