Extech Instruments RHT510 User manual

USER MANUAL
Hygro-Thermometer
Model RHT510
Additional User Manual Translations available at www.extech.com

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Introduction
Thank you for selecting the Extech Model RHT510. This hand-held device measures Relative
Humidity, Air temperature, Dew point temperature, Wet bulb temperature, and Type K
temperature (using external probe). This device is shipped fully tested and calibrated and, with
proper use, will provide years of reliable service. Please visit our website (www.extech.com) to
check for the latest version and translations of this User Manual, Product Updates, Product
Registration, and Customer Support.
Features
•Backlit LCD with Display Hold
•Light weight, ergonomic design with lanyard
•Displays Relative Humidity and Temperature (Air, Type-K, Dew point, and Wet bulb)
•Selectable temperature units C/F
•MAX-MIN Recording
•Tripod Mounting
•Battery operated
Safety
Please read the entire User Manual and Quick Start before operating this device. Use the meter
only as specified and do not attempt to service or open the meter housing. Do not allow children
to handle the meter. Please dispose of batteries and meter responsibly and in accordance with
all applicable laws and regulations.

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Meter Description
1. Air Temperature/Humidity Sensor
2. Type K Temperature Probe Input
3. LCD Display
4. ON-OFF button
5. ▲button
6. Mode button
7. Backlight button
8. SET and ▼button
9. Record button (MAX-MIN)
10. Display Hold button
Note: Battery compartment and tripod mount on back of meter
LCD Description
1. Type K Temperature Icon
2. Function Icons
3. MAX-MIN Record Icon
4. MAX Display Icon
5. MIN Display Icon
6. Display Hold Icon
7. Battery Status Indicator
8. Auto Power OFF (APO)
9. Primary Display
10. Secondary Display

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Operation
Basic Use
1. Short press the power button to power the meter. If the LCD does not switch on, check
the batteries located in the rear battery compartment.
2. Place the sensor in the testing environment.
3. View the measurement on the meter’s display.
4. To power OFF the meter, short press the button.
Mode Selection
Press the Mbutton to select the mode of operation. The meter has four (4) modes: Relative
Humidity %, Dew point temperature, Wet bulb temperature and Type K temperature (external
probe required). Release the Mbutton to make a selection.
Display Hold
Short press the Hbutton to freeze or unfreeze a reading on the display. The Display Hold and
APO functions are not operational in record mode.
LCD Backlight
The LCD is equipped with backlighting for easier viewing, especially in dimly lit areas. Press the
backlight button to turn the backlight on. The backlight will automatically turn off after 10
seconds.
Type K Measurement
Insert the optional Type K temperature probe into the Type K temperature probe socket (left
side of meter). Use the mode (M) button to set the mode of operation to Type K temperature
and view the readings on the display.
MAX-MIN Recording
The meter records the maximum and minimum values over time.
Note: Display Hold, Auto Power OFF setup, and the Power button do not function in Record
mode.
1. Press the Rbutton to enter the Record mode. The record icon will appear on the
display. The maximum and minimum values will be recorded and updated during the
measurement period.
2. Press the Rbutton to display the maximum value recorded over time. The icon and
maximum value will appear on the display.
3. Press the R button to display minimum value recorded over time. The icon and minimum
value will appear on the display.
4. Press the Hbutton to reset the recorded data. The previously recorded MAX-MIN readings
will be cleared and the meter will start recording new MAX-MIN readings.
5. Long press the Rbutton to exit the record mode.

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Auto Power OFF Control
In order to conserve battery life, the meter will automatically shut off after approximately 10
minutes of inactivity. The APO icon appears in the display when APO is selected.
To set APO ON or OFF as the default condition:
1. Long press SET button to enter APO mode. The bottom display will show ‘PoFF’.
2. Press the ▲or ▼button to turn the APO ON (YES) or APO OFF (NO).
3. Press the Rbutton to save the selection.
4. Wait approximately 10 seconds for the meter to return to normal operation.
Temperature Units Selection (C/F)
1. Long press SET button. The bottom display will show ‘PoFF’.
2. Press the Rbutton. The bottom display will show t-CF’.
3. Press the ▲or ▼button to select C or F.
4. Press the Rbutton to save the selection.
5. Wait approximately 10 seconds for the meter to return to normal operation.
Maintenance
Battery Replacement
1. Power OFF the meter.
2. Remove the flat head screw that secures the battery compartment at the back of the
meter.
3. Open the battery compartment and replace the 3 AAA batteries observing correct polarity.
Re-assemble the meter before use.
Safety: Please dispose of batteries responsibly; never dispose of batteries in a fire, batteries may
explode or leak. If the meter is not to be used for 60 days or more, remove the batteries and store
separately.
Never dispose of used batteries or rechargeable batteries in household waste.
As consumers, users are legally required to take used batteries to appropriate collection
sites, the retail store where the batteries were purchased, or wherever batteries are
sold.
Disposal: Do not dispose of this instrument in household waste. The user is obligated to
take end-of-life devices to a designated collection point for the disposal of electrical and
electronic equipment.
Cleaning and Storage
Periodically wipe the case with a damp cloth and mild detergent; do not use abrasives or
solvents.

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Specifications
Electrical Specifications (23±5°C)
Humidity/Air Temperature
Unit Range Resolution Accuracy
%RH 10 to 95 0.1 <70%: ±(4%RH)
≥70%: ±(4%rdg + 1.2%RH)
Temp oC 0 to 50 0.1 ±1.2oC
Temp oF 32 to 122 0.1 ±2.5oF
Type K Thermocouple (external probe)
Unit Range Resolution Accuracy*
Type K Temp oC
-50.0 to 1300.0 0.1 ±(0.4%rdg + 0.5 oC)
-50.1 to -100.0 0.1 ±(0.4%rdg + 1.0 oC)
Type K Temp oF
-58.0 to 2372.0 0.1 ±(0.4%rdg + 1.0 oF)
-58.1 to -148.0 0.1 ±(0.4%rdg + 1.8 oF)
*Accuracy spec. does not include additional error introduced by the external probe
Dew Point Temperature
oC -25.3 to 49.0 0.1 Calculation based on
humidity/temp values.
oF -13.5 to 120.0 0.1
Wet Bulb Temperature
oC -5.4 to 49.0 0.1 Calculation based on
humidity/temp values.
oF 22.2 to 120.0 0.1

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General Specifications
Display Backlit LCD 35 x 30mm (1.38 x 1.18”)
Measurements Humidity/Temp; Dew Point; Wet Bulb; Type K Temp.
Input Overload Display “----“
Tripod Mount On rear panel
Power 1.5V AAA batteries (3)
Power Consumption Approx. 5mA DC
Automatic Power Off After approx. 10 minutes of inactivity
Operating Temperature 0 to 50oC (32 to 122oF)
Operating Humidity 95% RH max
Storage Temperature -10 to 60oC (14 to 140oF)
Storage Humidity 10 to 75% RH
Dimensions/Weight 153 x 45 x 20mm (6.0 x 1.8 x 1.2”) /160g (5.64oz)
Copyright ©2017 FLIR Systems, Inc.
All rights reserved including the right of reproduction in whole or in part in any form
ISO 9001 Certified
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