Dwyer THI-10 User Manual

Bulletin H-THI-10

SECOND DISPLAY

MAIN DISPLAY

Model THI-10 Digital Thermohygrometer

Specifications - Installation and Operating Instructions

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The Model THI-10 Digital Thermohygrometer accurately measures
relative humidity and ambient temperature. Up to 99 readings can be
stored in non-volatile memory allowing the HVAC technician to record the
data after returning to the office. This compact thermohygrometer also
features user selectable engineering units, Maximum/Minimum functions,
dew point, and wet bulb temperature measurements. The Model THI-10
includes a soft carrying case with a belt loop for easy transportation.

OPERATING INSTRUCTIONS
Measurements

Press the “ ” button to turn the meter on.

Press and hold the HOLD button to toggle the humidity and temperature
displays.

Press the DEW/WET/%RH button to display the dew point. While
displaying dew point, press the DEW/WET/%RH button again to display
the wet bulb temperature.

Data Hold

Press the HOLD button to freeze the readings in both displays.

The “H” icon and the last readings will appear in the display.

The dew point and wet bulb temperature can be viewed while in Hold
mode.

In order to return to normal operation, press the HOLD button and the “H”
icon disappears from the display.

SPECIFICATIONS
Service: Humidity & temperature detection in air.
Range: Relative Humidity: 1 to 99% (non-condensing);

Temperature: -4 to 140°F (-20 to 60°C).

Accuracy: Relative Humidity: ±3%; Temperature: ±1.5°F (±0.8°C).
Display: Dual LCD Display (4 digit upper display / 3 digit lower display).
Temperature Limits: Ambient: 32 to 144°F (0 to 60°C).
Resolution: Relative Humidity: 0.1%; Temperature: 0.1°.
Power Requirements: 9V alkaline battery.
Battery Life: Approximately 200 hours.
Weight: 5.6 oz (160 g).
Agency Approvals: CE.

MEMORY
Storing data

Store measurement data by pressing the “MEM” button. The screen will
briefly display an “M” and the memory address number.

Retrieving Data

Press the READ button to cycle through the stored data.

Press and hold the READ button to exit memory and return the meter to
normal operation.

The meter’s internal memory can store up to 99 readings. When this limit
is reached, the screen will display “Full”. The memory must be cleared
before anymore readings can be stored.

Clearing the Memory

Turn the meter off.

Hold down the “MEM” button while powering on the meter.

“Clr” will appear on the screen when the stored data is erased.

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: [phone] e-mail: [e-mail]

Phone: [phone] www.dwyer-inst.com

MAXIMUM / MINIMUM MODE

This mode allows the user to view current maximum and minimum
readings.

AUTOMATIC POWER OFF (SLEEP MODE)

The meter will automatically power off after the factory default setting of 30
minutes.

Upon entering this mode, an elapsed timer meter is reset.

This allows the user to view temperature and humidity measurements with
the elapsed timer meter displayed.

• Press the “MX/MN” button to enter this mode.

• Press the “MX/MN” button to cycle through maximum and minimum
measurements below.

Maximum Humidity

& Temperature

Maximum Humidity

& Elapsed Time

(min:sec)

Maximum Humidity

& Elapsed Time

(day:hour)

Maximum Temperature

& Humidity Reading

Maximum Temperature

& Elapsed Time

(min:sec)

Maximum Temperature

& Elapsed Time

(day:hour)

Minimum Temperature

& Humidity Reading

Minimum Temperature

& Elapsed Time

(min:sec)

Minimum Temperature

& Elapsed Time

(day:hour)

Minimum Humidity

& Temperature

• To adjust the automatically power off time setting, begin by turning the
meter off.

• Hold the HOLD button while powering on the meter and release after
the first beep.

• Press the HOLD button to cycle through the below settings.

001: To disable auto power off function
002: 1 minute auto power off
003: 3 minute auto power off
004: 5 minute auto power off
005: 10 minute auto power off
006: 15 minute auto power off
007: 30 minute auto power off
008: 59 minute auto power off

• Press the MX/MN button to select the desired setting.

NOTICE

The auto power off function is activated each time you turn on the meter
and is automatically disabled when in MX/MN mode.

SETTING TEMPERATURE UNITS

The thermohygrometer can measure °F or °C.

• To change the units, turn on the unit by pressing the “ ” button.

• Hold down the “°C/°F” for 5 seconds to toggle the two units of
measurement.

BATTERY REPLACEMENT

The thermohygrometer incorporates visual low battery indication as
follows.

“BT”: battery power is not sufficient for accurate testing. When the low
battery icon indicates the battery is low, the battery should be replaced
immediately.

• The battery is located in the rear of the unit.

• Remove the cover and remove the battery.

• Insert one 9V battery.

Minimum Humidity

& Elapsed Time

(min:sec)

Minimum Humidity

& Elapsed Time

(day:hour)

NOTICE

It is important to allow the thermohygrometer to power off before replacing
the batteries otherwise the unit may malfunction. Dispose of used batteries
promptly and keep away from children.

MAINTENANCE

Upon final installation of the Model THI-10 Digital Thermohygrometer, no
routine maintenance is required. A periodic check of system calibration is

• Press the DEW/WET/%RH button to view the current maximum or
minimum dew point and wet bulb temperature.

• Hold the MX/MN button for two seconds to exit MIN/MAX mode and
return to normal operation (this also resets the MIN/MAX values).

recommended. The Model THI-10 is not field serviceable and should be
returned if repair is needed (field repair should not be attempted and may
void warranty). Be sure to include a brief description of the problem plus
any relevant application notes. Contact customer service to receive a
return goods authorization number before shipping.

©Copyright 2008 Dwyer Instruments, Inc. Printed in U.S.A. 9/08 FR# R6-443664-00

DWYER INSTRUMENTS, INC.

Phone: [phone] www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: [phone] e-mail: [e-mail]