This unique meter oers several features, such as; the sensor is protected
by tunable cap, it’s pocket-sized, battery operated. It quickly and easily
measures humidity, dry bulb, dew point, wet bulb, external temperature
as well as temperature dierential measurements. The psychrometer is a
micro-processor design. A must device for HVAC engineers use. No need
to whirl the meter or refer to the chart.
For service on this or any other REED product or information on other
REED products, contact REED Instruments at info@reedinstruments.com.
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INSTRUMENTS
Features
• Measures humidity, wet bulb, dew point, air temperature plus external
probe temperatures (requires 87P6 probe)
• Simultaneous display with %RH, temperature and dew point or wet
bulb or external probe temperature (requires 87P6 probe)
• Calculates T1-T2, Air temperature – External probe temperature
(requires 87P6 probe)
• Triple display with backlighting
• Max/Min readings
• Sensor cap closes to protect probe during storage
• Retrieve Max/Min/Avg readings from stored data
• Real time clock
• Triple LCD digital display
• Pocket size, ts easily in your pocket
• Low battery indication
• Fast response
• Accurate reading
• Maximum record function
• Minimum record function
• Dew Point calculated in seconds
• Wet Bulb calculated in seconds
• Microprocessor circuitry for reliability
• Auto power o, time frame selectable
• Disable power o
• Batteries included (2 x AAA)
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INSTRUMENTS
Specifications
FUNCTION RANGE RESOLUTION ACCURACY
Humidity: 0 to 100% RH 0.1% RH ±3% RH
Dew Point: -109.7 to 122°F/ 0.1°F/°C
-78.7 to 50°C
Wet Bulb: -69 to 122°F/ 0.1°F/°C
-21.6 to 50°C
Internal Temp.: -4 to 122°F/ 0.1°F/°C ±1°F/0.6°C
-20 to 50°C
External Temp. -4 to 158°F/ 0.1°F/°C ±1°F/0.6°C
-20 to 70°C
Power Supply: 2 x 1.5V AAA batteries (included)
Dimensions: 7 x 1.9 x 1" (179 x 48 x 25mm)
Weight: 3.3 oz (95g)
Accessories: Optional External Temperature Probe (Model 87P6)
Optional Calibration Salt Bottles; 33% (Model RHA-33)
& 75% (Model RHA-75)
Soft Carrying Case (Model CA-03)
WARNING
Be sure to open the
sensor protection cap
before starting the
measurement in order
to get an accurate
value.
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INSTRUMENTS
Instrument Description
1) Power On/O Button
2) °C/°F Button, Switch between
°C and °F
3) MODE Button, Switch between
Db & DP (Db=Air Temperature)
4) HOLD Button
a) Hold display
b)
Power Button +
HOLD = Non-Sleep mode
(The default setting is auto-sleep
in 5 minutes)
5) RESET Button,
Reset Min/Max memory
6) MN/MX Button
a) Display minimum value of
memory from when the meter is
turned on to now.
b) Display maximum value of
memory from when the meter
is turned on to now.
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INSTRUMENTS
Measuring Procedures
WARNING
Plugging in an external probe when the meter is on, could cause
a "ER 5" error in the min. or max. mode for external temperatures.
Press the "RESET" button to remove the error.
Auto Power Off (Sleep Function)
The meter will turn itself o after 5 minutes.
To override Auto Power O function, press + HOLD while the meter is
o. When "n" appears (see gure A), release the HOLD button. The meter
is now in Non-Sleep Mode.
Figure A
Mode Options
1. Turning on the protective sensor cap in counterclockwise direction.
2. Turn meter on by pressing power button (see gure B).
3. Press C/F key for more than 1 second to convert reading to desired
unit. Both the temperature and relative humidity measurement will
display simultaneously (see gure C).
Figure B
requires 87P6 probe
Figure C
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INSTRUMENTS
Data Hold Function
1. Press "HOLD" button until (HLD) appears in display.
2. The current reading is now held and will not change until the
Hold function is cancelled (see gure D).
3. Press "HOLD" button again to cancel the Hold function.
Figure D
The Hold function can be used on humidity,
dew-point, dry bulb/T1, external temperature/
T2, wet bulb and temperature dierence.
Dew Point Function
1. Press MODE button until "DP" appears on display.
2. Select to display dew point or dry bulb (air temp.) in any mode while the
unit is on (see gure E).
Figure E
Figure E1
Wet Bulb Function
Turn the meter on by pressing power button.
You will see "Wb" temperature indicated on the display (see gure E1).
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INSTRUMENTS
External Temperature Function
1. Plug the optional external probe (Model 87P6) into the meter.
2. Press the RESET button until "Ex" appears on display.
The meter will now display external probe temperature. See gure F.
Figure F
Note: If the probe isn’t plugged in meter,
"Ex" won’t appear on display even when
pressing the RESET button.
Min./Max. Function
1. Press and hold MN/MX button until (MIN) appears on the display
(see gure G). The display is now showing minimum humidity
and temperature readings currently in the memory.
2. Press and hold MN/MX button again until (MAX) appears on the display
(see gure H). The display is now showing maximum humidity and
temperature readings currently in the memory.
3. To return to the current temperature and humidity readings press and
hold the MN/MX button until Min or Max disappear from the display.
4. Press the RESET or the MN/MX button for more than two seconds to
clear currently in the memory.
Figure G
continued ...
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WARNING
While checking the MIN/MAX value for "Ex" don’t replace the probe
or you will get an error code. If you don’t plug the probe into socket
before turning the meter on, the error code will also appear when you
check the MIN/MAX value.
Note: Low battery power tends to give inaccurate readings, therefore
make sure you have enough power.
Calibration
WARNINGS
• You can exit the calibration procedure without saving the data in
the memory by pressing the "ON/OFF" button before step 4. At
step 4, press the "ON/OFF" button to exit the calibration mode.
• Auto power o is disabled in calibration mode.
•
For the highest accuracy, the calibration should be operated at 23°C.
• If the reading is out of 75.3% 0.5% at step 4, this indicates the
calibration has failed. See troubleshooting section below.
1. Turn the meter o and plug the sensor probe into 33% salt bottle.
Press the "ON/OFF + C/F " buttons for more than one second to enter
calibration mode.
2. "32.8%" will ash on the display, when "---.-" is showing on the display,
that means the values are invalid in the calibration process. After 30
min, the ashing will stop to indicate the procedure is nished.
3. Move the sensor to 75% salt bottle and press "MN/MX" for more than
one second to enter 75.3% calibration. "75.3%" will ash
on the display.
4. The ashing will stop after 30 minutes, at this point the entire
calibration is completed and the calibration data has been
saved in memory.
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INSTRUMENTS
Troubleshooting
Power is on but the display is not working:
A. Make sure you’re pressing the ON/OFF button for more than 1 second
B. Verify that the batteries are in place and that they are in proper contact
and in the correct polarity.
C. Replace with new batteries and try again.
D. Remove the batteries for one minute, put them back in and try again.
Display is not turning on:
A. Verify that the Low Battery symbol
display disappears, if yes, replace with a new battery.
B. Check if the sleep mode is active. If yes, press the
buttons to disable auto power o function.
isn’t displayed before the
power + HOLD
Er 1
Circuit error in RH measurement
channel, return the meter to place
of purchase for repairs.
Er 2
Circuit error in internal temperature
measurement channel, return the meter to place of purchase for repairs.
Er 3
Circuit error in reference resistor
channel, return the meter to place
of purchase for repairs.
Er 4
Internal temp. is out of the range.
Er 5
External temp. is out of the range.
WARNING
Plugging in an external probe when the meter is on, could cause
a "ER 5" error in the min. or max. mode for external temperatures.
Press the "RESET" button to remove the error.
Note:
Dry Bulb temperature means air (internal) temperature.
Dew point & Web Bulb are calculated from internal temperature.
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INSTRUMENTS
Battery Replacement
The
when the battery power is low. If the batteries are not replaced the
accuracy of the reading will be aected.
1. Open the battery cover at the back of the meter
2. Insert 2 new AAA batteries and make sure the batteries
3. Reinstall the cover.
Battery symbol appears on the display at the top/right corner
and remove the batteries.
are in the correct polarity.
Warranty
The meter is warranted to be free from defects in material and
workmanship for a period of one year from the date of purchase.
This warranty covers normal operation and does not cover battery,
misuse, abuse, alteration, tampering, neglect, improper maintenance or
damage resulting from leaking batteries. Proof of purchase is required for
warranty repairs. The warranty is void if the meter has been opened.
For service on this or any other REED product or information on other
REED products, contact REED Instruments at info@reedinstruments.com.