General Tools & Instruments EP8709 Instruction Manual
CALIBRATABLE
4-FUNCTION
PSYCHROMETER
USER’S MANUAL
EP8709
Please read this manual carefully and
thoroughly before using this product.
TABLE OF CONTENTS
Introduction . . . . . . . . . . . . . . . . . . 2 –4
Key Features . . . . . . . . . . . . . . . . . . . . 4
What’s in the Box . . . . . . . . . . . . . . . . 4
Product Overview . . . . . . . . . . . . . 4 –6
Setup Instructions . . . . . . . . . . . . . . . . 7
Install Battery . . . . . . . . . . . . . . . . . . 7
Operating Instructions . . . . . . . . . 7 – 10
Making Basic Measurements . . . 7 –9
Tracking Min and Max Levels . . 9 – 10
Calibrating the Meter . . . . . . . . 10 – 14
Specifications . . . . . . . . . . . . . . . . . . 15
Operating & Maintenance Tips . . . . . 16
Warranty Information . . . . . . . . . . . . 17
Return for Repair Policy . . . . . . . . . . 18
INTRODUCTION
Thank you for purchasing General Tools &
Instruments’ EP8709 Calibratable 4Function Psychrometer. Please read this
user’s manual carefully and thoroughly
before using the instrument.
The EP8709 can measure any
environment’s ambient temperature,
relative humidity (RH), and dew point and
wet bulb temperatures. These
measurements are typically made by three
groups of users:
2
• Water damage restoration contractors
• HVAC/R system installers and technicians
• Professionals charged with monitoring
and maintaining the environment of
facilities such as office buildings,
greenhouses, food and equipment storage
facilities, wineries, freezers, shipping
containers, computer rooms, labs,
libraries, museums and saunas.
The dew point is the temperature below
which the water vapor in a volume of air at
a given constant barometric pressure will
condense into liquid water at the same rate
at which it evaporates. Condensed water is
called dew when it forms on a solid surface.
Another way to think of the dew point is as
an air saturation temperature associated
with relative humidity (RH). A high RH value
indicates that the dew point is close to the
current ambient air temperature. At 100%
RH, the dew point temperature is equal to
the ambient temperature because the air is
completely saturated with water.
The wet bulb temperature is the
temperature that a volume of air would
have if it were cooled to saturation (100%
RH) by the evaporation of water into it, with
the latent heat coming from the volume of
air. It is the lowest temperature that can be
reached under current ambient conditions
by the evaporation of water only. The wet
3
bulb temperature is the temperature you
feel when your skin is wet and exposed to
moving air as opposed to the actual air
temperature—the dry bulb temperature.
The EP8709 is powered by one “9V” battery
(included).
KEY FEATURES
• Jumbo backlit display with 2-line readout
• Field calibratable using optional 33% and
75% salts
• Data hold and Min/Max functions
• °F/°C switch
• 20-minute Auto Power Off function
• Low battery indicator
WHAT’S IN THE BOX
The EP8709 comes fully assembled in a box
along with a sensor protection cap, a “9V”
battery and this user’s manual.
PRODUCT OVERVIEW
Figure 1 shows all of the controls, indicators
and physical structures on the front, top and
bottom of the EP8709. Figure 2 shows all
text and icons that could appear on the
unit’s LCD. Familiarize yourself with the
positions and functions of all buttons,
structures and icons before moving on to
the Setup Instructions and Operating
Instructions.
4
A
B
F
G
H
Fig. 1. The EP8709’s controls, indicators
and physical structures
A. Humidity and temperature sensors
B. LCD
C. (Power on/off) button
D.
F/C
button
E.
WBT
(wet bulb temperature) button
F.
DEW
button
G.
HOLD
button
H.
MAX/MIN
button
I. Battery compartment
C
D
E
I
5
A
J
B
C
D
H
G
I
Fig. 2. All possible display indications and
their meanings
A. Low battery icon
B. Data hold indicator
C. Maximum reading indicator
D. Minimum reading indicator
E. °C indicator
F. °F indicator
G. Wet bulb temperature indicator
H. Dew point temperature indicator
I. Temperature readout
J. Relative humidity (RH) readout
E
F
6
Loading...