Digi-Sense 20250-04 User manual

User Manual
THE STANDARD IN PRECISION MEASUREMENT
Infrared Thermometer
with 10:1 Distance-to-Sight Ratio
with NIST-Traceable Calibration
Model 20250-04

2
Introduction
The Digi-Sense Infrared Thermometer (Model 20250-04)
with 10 to 1 distance-to-sight ratio offers fast response
and high accuracy. Advanced features include data Hold,
Max/Min readings, and auto power-off. The instrument is
fully tested and calibrated to NIST-traceable standards.
Careful use of this meter will provide years of reliable
service.
Unpacking
Check individual parts against the list of items below. If
anything is missing or damaged, please contact your
instrument supplier immediately.
1. Meter
2. One 9 V battery
3. User manual
4. NIST-traceable calibration report with data

3
Key Features
• 10:1 Distance-to-sight ratio
• 2.5% basic accuracy
• Fixed emissivity (0.95)
• Precise noncontact measurements
• Laser sighting
• User-selectable °C or °F units
• Automatic data Hold
• MAX/MIN temperature displays
• Automatic selection range and display resolution
• Trigger lock
• Backlight LCD
• Automatic power-off to conserve battery life

4
Meter Description
1. IR sensor
2. Laser pointer beam
3. LCD
4. °C/°F button
5. MAX/MIN button
6. Laser / Backlight button
7. Measurement trigger
8. Battery cover
9. Handle grip
3
2
5
6
1
4
7
8
9

5
Display Layout
1. Fixed emissivity (0.95) scan icon
2. Temperature readout
3. Max and Min reading icons
4. SCAN measuring indicator
5. Data Hold icon
6. Laser point indicator
7. Low-battery indicator
8. °C or °F temperature units
8
4 5 6 7
3
2
1

6
How it Works
Infrared thermometers measure the surface tempera-
ture of an object. The unit’s optics sense emitted,
reflected, and transmitted energy, which is collected
and focused onto a detector. The unit’s electronics
translate the information into a temperature reading
which is displayed on the unit. The laser is used for
aiming purposes only.
Field of View
Make sure that the target is larger than the unit’s spot
size. The smaller the target, the closer you should be
to it. When accuracy is critical, make sure the target
is at least twice as large as the spot size.
Distance and Spot Size
As the distance (D) from the object increases, the
spot size (S) of the area measured by the unit
becomes larger.
Locating a Hot Spot
To find a hot spot, aim the thermometer outside the
area of interest, then scan across with an up-and-
down motion until you locate hot spot.

7
Emissivity
Emissivity is a term used to describe the energy-
emitting characteristics of materials. Most (90% of
typical applications) organic materials and painted
or oxidized surfaces have an emissivity of 0.95
(fixed in the unit). Inaccurate readings will result
from measuring shiny or polished metal surfaces.
To compensate, cover the surface to be measured
with black tape or flat black paint. Allow time for the
tape to reach the same temperature as the material
underneath it. Measure the temperature of the tape
or painted surface. (Refer to table on page 8.)
Good Measuring Practices
Holding the meter by its handle, point the IR sensor
toward the object whose temperature is to be mea-
sured. The meter automatically compensates for
temperature deviations from ambient temperature.
Keep in mind that it will take up to 30 minutes for
the IR sensor to stabilize if going from ambient tem-
peratures to a much higher (or lower) temperature
measurement.
Reminders
• The unit is not recommended for measuring shiny
or polished metal surfaces (stainless steel, alumi-
num, etc.). See Emissivity above.
• The unit cannot measure through transparent
surfaces such as glass. It will measure the surface
temperature of the glass instead.
• Steam, dust, smoke, etc. can prevent accurate
measurement by obstructing the unit’s optics.

8
Emissivity Values
Substance Thermal
emissivity Substance Thermal emissivity
Asphalt 0.90 to 0.98 Cloth (black) 0.98
Concrete 0.94 Human skin 0.98
Cement 0.96 Lather 0.75 to 0.80
Sand 0.90 Charcoal (powder) 0.96
Earth 0.92 to 0.96 Lacquer 0.80 to 0.95
Water 0.92 to 0.96 Lacquer (matte) 0.97
Ice 0.96 to 0.98 Rubber (black) 0.94
Snow 0.83 Plastic 0.85 to 0.95
Glass 0.90 to 0.95 Timber 0.90
Ceramic 0.90 to 0.94 Paper 0.70 to 0.94
Marble 0.94 Chromium oxides 0.81
Plaster 0.80 to 0.90 Copper oxides 0.78
Mortar 0.89 to 0.91 Iron oxides 0.78 to 0.82
Brick 0.93 to 0.96 Textiles 0.90

9
Setup and Operation
1. Hold the meter by its handle grip and point it toward
the surface to be measured.
2. Pull and hold the trigger to turn the meter on and
begin testing. The display will light if the battery is
good. Replace the battery if the display does not
light.
3. While measuring, the SCAN icon will appear in
the upper left-hand corner of the LCD.
4. Press the °C/°F button to select your desired
temperature units.
5. Press the Laser / Backlight button to turn on the
laser pointer. When the laser is on, the Laser icon
will appear on the LCD. Quickly press the Laser /
Backlight button again to turn laser off.
6. Press and hold the Laser / Backlight button to turn
the backlight on or off.
7. Release the trigger and the HOLD icon will appear
on the LCD indicating that the reading is being held.
8. Use the MAX/MIN button to display the maximum
or minimum value.
9. To conserve battery life, the meter automatically
powers down in 10 seconds once the trigger is
released.

10
Specifications
Temperature range –4 to 630°F (–20 to 332°C)
Resolution 0.1°F/C
Accuracy ±2.5 of reading or ±4.5°F (2.5°C)
Response time Less than 1 second
Emissivity Fixed at 0.95
Distance-to-sight ratio
(field of view)
D/S = Approximately 10:1 ratio
(D = distance, S = spot)
Laser Single Class 2 (II) Laser
Spectral range 6 to 14 µm
Out-of-range indication LCD will show “Hi/Lo“
Operating temperature 32 to 122°F (0 to 50°C)
Storage temperature –14 to 140°F (–10 to 60°C)
Power One 9 V battery
Field of View
The meter’s field of view is 10:1, meaning that if the meter
is 10 inches from the target, the diameter of the object
under test must be at least 1 inch. Other distances are
shown below in the field of view diagram below. Make
sure that the target is larger than the unit’s spot size.
The smaller the
target, the closer
you should be to it.
When accuracy is
critical, make sure
the target is at least
twice as large as the
spot size.

11
Safety
• Use extreme caution when the
laser beam is turned on.
• Do not let the laser beam enter your eye, another
person’s eye or the eye of an animal.
• Be careful not to let the laser
beam on a reflective surface
strike your eye.
• Do not allow the laser light
beam to impinge on any
gas which can explode.
Maintenance, Recalibration, and Repair
Cleaning and Storage
• The meter should be cleaned with a damp cloth and
mild detergent when necessary. Do not use solvents
or abrasives.
• Store the meter in an area
with moderate temperature
and humidity (refer to the
operating and storage
temperatures on page 10).
Battery Replacement
If the battery power is insufficient,
the Low Battery icon will appear
on the LCD. Open the battery cover
and replace the 9 V battery. Securely
close the cover.
9V battery
Open the
battery cover

For Product and Ordering Information, Contact:
Toll-Free: 1-800-323-4340
Phone: [phone]
Fax: [phone]
ColeParmer.com/Digi-Sense
Toll-Free: 1-800-358-5525
Phone: [phone]
Fax: [phone]
Davis.com/Digi-Sense
1065DGMAN_20250-04 Rev.1
Manual Part No. 00100-38
Maintenance, Recalibration, and Repair (Cont.)
It is recommended that Digi-Sense products are calibrated
annually to ensure proper function and accurate measure-
ments; however, your quality system or regulatory body
may require more frequent calibrations. To schedule your
recalibration, please contact InnoCal, an ISO 17025 calibra-
tion laboratory accredited by A2LA.
Phone: 1-866-INNOCAL (1-866-466-6225)
Fax: [phone]
E-mail: [email protected]
Web: InnoCalSolutions.com