Dwyer 485B - Manual

Model 485B Digital Thermo-Hygrometer is a versatile, compact, hand-
held instrument for measuring percentage of relative humidity and
temperature in °F or °C. Dew point and wet bulb temperatures are
derived from relative humidity and temperature measurements and
displayed on the LCD. The hold key freezes the current temperature and
relative humdity readings for situations where readings fluctuate. Store
up to 99 readings with the non-volatile memory function – ideal for
technicians needing to take multiple readings for later analysis.
Battery Installation
The unit is shipped with a separate 9 volt alkaline battery which must be
installed before operation. Remove the two screws holding the bottom
endcap in place and remove it. Connect the battery to the enclosed
battery clip, observing correct polarity. Be careful not to trap the wires
between the case or foam pad which retains the battery. This could
make it difficult to install the battery or remove it later for replacement.
Be sure the rubber gasket is properly seated in the gasket channel and
replace the endcap. Note that the endcap will only fit one way because
the holes are slightly off-center. Place the “Z” shaped wrist strap clip in
one of the screw recesses and replace the screws. Do not overtighten.
Attach the wrist strap to the clip.
When battery replacement becomes necessary, use only 9 volt alkaline
type batteries such as a Duracell
® MN1604, or Eveready ® 522 or
equivalent. Zinc-carbon types, often labeled Heavy-Duty are not
recommended because of their shorter life and an increased potential
for leakage. Alkaline batteries are a better value because they last
typically up to three times longer in this device.
Low Battery Indicator
A weak battery may cause improper operation or inaccurate
measurements. A low battery indicator ( ) is provided on the display
to show when the battery needs to be replaced. Although the unit may
appear to function and read properly, the accuracy of the readings
cannot be guaranteed when the ( ) indicator is empty of power
segments. Replace the battery with a fresh one. Do not leave an
exhausted battery in the unit due to potential battery leakage.
SPECIFICATIONS
Service: Humidity, temperature, wet bulb and dew point temperature
detection in clean air.
Temperature Limits:
Process: -40 to 176°F (-40 to 80°C);
Ambient: 5 to 125°F (-15 to 51°C).
Range Relative Humidity: 0 to 100% (non-condensing).
Accuracy Relative Humidity: ±2% FS over 10 to 90% @ 77°F (25°C).
Range Temperature: -20 to 140°F (-28 to 60°C).
Accuracy Temperature: ±0.9°F @ 72°F (±0.3°C @ 25°C).
Display: 4.5 digit LCD.
Resolution: 0.1%, 0.1 °F/°C.
Probe Length: 8˝ (203 mm) insertion.
Power Requirements: 9V alkaline battery included.
Weight: 16 oz (454 g).
Agency Approvals: CE, RoHS.
Model 485B Digital Hygrometer
Specifications and Operating Instructions
Bulletin TE-485B
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: 219/872-9057 e-mail: [email protected]
OPERATING INSTRUCTIONS
Duracell ® is a registered trademark of The Gillette Company
Eveready ® is a registered trademark of Eveready Battery Company, Inc.