Centech 92242 Quick reference guide

ASSEMBLY & OPERATING INSTRUCTIONS
92242
®
DIGITAL THERMOMETER
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit our Web Site at www.harborfreight.com
Copyright©2004 by Harbor Freight Tools®. All rights reserved. No portion of this manual or
any artwork contained herein may be reproduced in any shape or form without the
express written consent of Harbor Freight Tools.
For technical questions and replacement parts please call 1-800-444-3353.

SKU 92242 For technical questions please call 1-800-444-3353. Page 2
THANK YOU for choosing a HARBOR FREIGHT TOOLS product. For future reference, please
complete the owner’s record below:
Model______________ Serial No._____________ Purchase Date_______________
SAVE THE RECEIPT, WARRANTY AND THESE INSTRUCTIONS. It is important that you read the
entire manual to become familiar with the unit BEFORE you begin assembly.
Technical Specifications
Viewer Display: Large 3-1/2” digital liquid crystal with maximum reading of 1,999
Temperature Scale: Can be set to read in Celsius (C), Fahrenheit (F) or Kelvin (K)
Measurement Range: -50°Celsius to 1,300°Celsius;-58°Fahrenheit to 2000°Fahrenheit;223 Kelvin
to 1573 Kelvin
Resolution: 1° C or 1°F, 0.1°C or 0.1°F, 1K
Accuracy: Accuracy is specified for operating temperatures over the range of 18°C to
28°C (64°F to 82°F) for one year, not including thermocoupler error.
+2°C----------------------- -50°C to 0° C
+4°F----------------------- -58°F to 32°F
+5K----------------------- 223K to 273K
+(0.5% reading +1°C)----0°C to 1000°C
+(0.8% reading +1°C)-----1000°C to 1300°C
+(0.5% reading + 2°F)----32°F to 2000°F
+(1.0% reading + 2K)-----273K to 1573 K
Power Supply: (1) 9V D/C battery
Safety Warnings and Precautions
WARNING:When using product, basic safety precautions should always be followed to
reduce the risk of personal injury and damage to equipment.
Read all instructions before using this product!
1. Keep work area clean. Cluttered areas invite injuries.
2. Observe work area conditions. Keep work area well lighted.
3. Store idle equipment. When not in use, the DigitalThermometer must be stored in a dry
location to inhibit rust. Always lock up products and keep out of reach of children.
4. Use the right product for the job. There are certain applications for which the Digital
Thermometer was designed. Do not modify the Digital Thermometer and do not use the
Thermometer for a purpose for which it was not intended.
5. Check for damaged parts. Before using any product, any part that appears damaged should
be carefully checked to determine that it will operate properly and perform its intended function.
Check for any broken or damaged parts and any other conditions that may affect its operation.
Replace or repair damaged or worn parts immediately.

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6. Do not operate product if under the influence of alcohol or drugs. Read warning labels on
prescriptions to determine if your judgment or reflexes are impaired while taking drugs. If there
is any doubt, do not operate the product.
7. Use only Batteries of the type recommended-size, 9V D/C.
8. Do not mix old and new batteries. Do not use different types of batteries.
9. Keep children away. Children must never be allowed in the work area. Do not let them handle
theDigitalThermometer.
10. Remove the battery if theThermometer is not used for a long period of time.
11. Repeated sharp flexing can break the thermocouple leads. Avoid sharp bends in the
leads, especially near the connector.
Note: Always switch to a fresh battery when tool performance begins to diminish.
This is a delicate instrument, do not drop or jar the Digital Thermometer.
Warning: The warnings, cautions, and instructions discussed in this instruction manual cannot
cover all possible conditions and situations that may occur. It must be understood by
the operator that common sense and caution are factors which cannot be built into
this product, but must be supplied by the operator.
Unpacking
When unpacking your Digital Thermometer, check to make sure the following parts are included. If
any parts are missing or broken, please call HARBOR FREIGHT TOOLS at 1-800-444-3353.
Assembly
Your Digital Thermometer requires only minor assembly. It is important that you read the entire
manual to become familiar with the product BEFORE you assemble and use the Digital
Thermometer. Before assembling and operating the DigitalThermometer be sure that you have all
parts described in the Parts List and Assembly Diagram located on the last pages of this manual.
Turning the Thermometer “ON” and “OFF”
1. Insert the battery into the battery compartment. Refer to the section on page 5 titled,
“Replacing the Battery.”
2. Turn on the Thermometer by pressing the “ON/OFF” Switch located at the top of the
Thermometer-see Figure 1 on page 4.

SKU 92242 For technical questions please call 1-800-444-3353. Page 4
Setting to the DesiredType of Measurement
The Thermometer readings can be set to be displayed in Celsius, Fahrenheit or Kelvin.
1. Turn on the Thermometer by pressing the “ON/OFF” Switch located at the top of the
Thermometer-see Figure 1.
2. TheThermometer will display a temperature along with a letter showing the present degree
setting. For example, a measurement of 70 degrees Fahrenheit will read 70 F. Degrees in
Celsius will be followed by a small C and Kelvin by a small K.
3. Press the C-Celsius, F-Fahrenheit or K-Kelvin button located at the bottom of the
Thermometer face-see Figure 2. TheThermometer will display the selected setting.
Displaying the Maximum Mode
1. TheThermometer can record and update the maximum values for the most recent readings.
Press the MAX button, which is one of four buttons, located on the right side of the
Thermometer face-see Figure 1.
2. Pressing the MAX button will cause theThermometer to remember, record and display the
most recent maximum temperature reached. The word “ Max” will be displayed along with
thetemperature.
3. To turn off the Maximum function, press the MAX button again.
Selecting Display in 1 Degree orTenths of a Degree
1. The Thermometer will allow you to choose to have the temperature displayed in increments
of degrees for Celsius and for Fahrenheit. You can have the temperature displayed in tenths
of a degree, such as 0.1°C or 0.1°F. You can have the temperature displayed in whole
degrees such as 1°C or 1°F-see Figure 1.
2. Pressing the Tenth of a Degree Key (“0.1”) will display the temperature in tenths of a degree-
see Figure 1.
3. Pressing the Whole number key (“1°”) will display the temperature in increments of 1 degree.
LCDDisplay
On/Off Button
Backlight Button
TemperatureCoefficient
Maximum
Celsius
Fahrenheit
Figure 1-Thermometer Control Buttons
TenthDisplay
Hold
WholeNumberDisplay
Kelvin

SKU 92242 For technical questions please call 1-800-444-3353. Page 5
Holding a Temperature Display
1. The “HOLD” key is located on the right side of the Thermometer face and is one of the four
buttons surrounding the “TYPE” button. Pressing the “HOLD” key will cause the
Thermometer to display the present readings. It will display only the present reading and will
stop all future measurements-see Figure 1.
2. To turn off the “HOLD” setting, press the “HOLD” key again. This will resume normal
display on ongoing measurements-see Figure 1.
Backlighting the Display
The Thermometer has a backlight feature which allows you to read the Thermometer display in
situations where there is not enough light-see Figure 1.
1. Press the Backlight key to light up the display.
2. Press the Backlight again to turn the backlight off.
Overload Display (1)
The digital display will indicate “1” when the input exceeds the measurement range selected-see
Figure1.
1. If the temperature you are measuring exceeds 199.9, change the display to read in
increments of 1-see section on Selecting Display in 1 Degree or Tenths of a Degree.
2. Make certain that the thermocouple connector is seated properly and that the leads are not
broken. Thermocouple Checking
1. First, allow time for the Thermometer to adjust to the ambient temperature. To check the
accuracy of the Thermocouple reading, place the end of the Thermocouple away from any
object. Press the Thermocouple Checking button (Tc) button. With the button down, the
Thermometer will display the temperature reading inside the unit. Record the temperature
reading.
2. Release the button and allow time for theThermometer to adjust to the ambient temperature.
TheThermometer will display the exterior temperature. Record the temperature reading.
3. The Thermocouple is reading correctly if the two temperatures are reading within the
accuracy range specified on page 2. For example, when the thermometer reads 74.7°F with
theTc button on, and 74.2°F with the button off. There is a .5 degree difference in
temperatureshown.
4. The degree of accuracy is + 4°F, or + .5% reading plus 2°. The reading is within this range
and is accurate. Note that if accuracy is off it is generally a problem with the
Thermocouple and not theThermometer.
Tripod
The Thermometer can be set onto a Tripod (not included). Thread the receptacle on the back of the
Thermometer onto the screw of theTripod-see Figure 2 next page. The thread on the tripod mount is
1/4”-20 and can be used with a tripod which fits this same size thread.

SKU 92242 For technical questions please call 1-800-444-3353. Page 6
Replacing the Battery
1. A symbol of a battery will appear on the lower right LCD display when the 9V battery is
running low and needs to be replaced.
2. Turn the Thermometer “OFF” by pressing the “OFF”button. Remove the thermocoupler.
3. Remove the rubber case which surrounds the Thermometer by gently pulling it off of the top
oftheThermometer.
4. Unscrew the bolt holding the Battery Cover in place-see Figure 2. Remove the Battery
Cover.
5. Insert a new 9V battery into the battery compartment. Attach the battery plug to the battery
making certain that the polarity is correct.
6. Replace the Battery Cover and thread back in the Screw keeping the Cover in place.
Replace the case covering the Thermometer.
Batteryconnections
Battery Cover Screws in here
Figure 3
Operation
1. Plug theThermocoupler into the top of theThermometer-see Figure 2.
2. Set the end of theThermocoupler at the place where you desire to measure temperature.
3. Turn the Thermometer “ON.”
4. The Thermometer has a stand which can be pulled out from the back and used to rest the
Thermometer for easy reading of display.
5. Turn the Thermometer “OFF”when you are done using it. Disconnect theThermocoupler.
Maintenance
1. Never immerse theThermometer in any fluid.
2. Store in a dry and safe location out of the reach of children.
2. Remove dust or stains with a soft lightly dampened cloth.
3. Remove the battery if you are not going to use theThermometer for a long period of time.
No replacement parts are available for theThermometer.
Figure 2
Tripodmount
Stand pulls out
for set up and
readingofthe
Thermometer
Thermocouple