User Manual
Professional Thermocouple Thermometer
with Dual Type K Inputs, Data Logging,
and Optional Infrared Wand
with NIST-Traceable Calibration
Model 20250-19
Enter
REC
DIF
THE STANDARD IN PRECISION MEASUREMENT
Introduction
The Digi-Sense Professional Thermocouple Thermometer (Model 20250-19)
with Dual Type K Inputs, Data Logging, and Optional Infrared Wand offers fast
response and high accuracy. This heavy-duty meter works with up to two type K
thermocouples and one optional infrared probe*. Advanced features include
data logging, USB interface, relative time clock, offset compensation, temperature differential, data Hold, Max/Min/Avg readings, and automatic 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. Two type K flexible probes
3. USB cable
4. Software
5. Carrying case
6. One 9 V battery
7. User manual
8. NIST-traceable calibration report with data
*Optional infrared wand (model 20250-24) must be ordered separately.
Key Features
• Large backlit display shows any combination of T1, T2, T3, T1–T2, T1–T3, T2–T3;
plus Max, Min, and Avg readings
• Relative time clock on Max/Min/Avg provides a time reference for major events
• Electronic Offset function allows compensation of thermocouple errors to
maximize overall accuracy
• USB interface
• Data logging capacity of 18,000 sampling points
• User-selectable readout in °C, °F, or Kelvin (K)
• 0.1°C / 0.1°F / 0.1 K resolution
• Scan function (T1, T2, T3, T1–T2, etc.)
• Automatic power-off (sleep) mode to conserve battery life
• Dual sensor inputs; accepts a wide variety of thermocouple type K probes
2
Meter Description
1
1. Thermocouple type K (T1) input
2
2. Thermocouple type K (T2) input
3. LCD
4. Enter button
5. Up  button
13
3
6. Rec/ button
7. °C/°F/K button
8. HOLD button
9. Power on/off button
12
4
Enter
REC
10. DIF/T1–T2–T3 button
6
11. MAX/MIN button
12. Setup /
Backlight button
7
11
8
13. IR (T3) input*
*Optional infrared wand (model 20250-24)
must be ordered separately.
5
DIF
10
9
Display Layout
1. Thermocouple TYPE K icon (this icon
flashes when meter is recording)
2. Infrared IR TEMP icon (requires Optional
IR wand sku number 20250-24)
3. Data HOLD icon
1
2
3
4
4. SETUP mode icon
5. Primary temperature display (T1, T2, T3,
T1–T2, T1–T3, or T2–T3 reading)
5
6. Secondary display (Max, Min, Avg, or
offset T1, T2, T3 reading)
6
7. Temperature unit icons (°C, °F, K)
8. Tertiary display (elapsed time or T1, T2,
T3 reading)
7
11
8
9. Low-battery indicator
10. Elapsed time (hour:min or min:sec)
9
10
11. MAX, MIN, AVG icons
3
Setup and Operation
1. Press Power on/off button to turn the unit on. The value immediately
shown is the number of data logging sample points remaining (from
18,000 to 0). After one second, the display will then switch to the
temperature measurement reading mode.
2. Press MAX/MIN button to step through the maximum, minimum, and
average readings. To exit the Max/Min/Avg mode, press MAX/MIN button for three seconds to return to normal operation.
3. Press °C/°F/K button to switch between Celsius (°C), Fahrenheit (°F), and
Kelvin (K).
4. Press HOLD button to freeze or unfreeze the displayed readings. The
screen shows the HOLD icon.
5. Use the DIF/T1–T2–T3 button to toggle between showing the T1 (type K),
T2 (type K), T3 (infrared), and T1–T2, T1–T3, T2–T3 (temperature differentials) measurement in the primary, secondary, or tertiary display.
6. Press Setup/Backlight button to turn on the backlight. Press it again to
turn off the backlight. Press Setup/Backlight button and hold for three
seconds to enter or exit the Setup mode. (See "Changing Setup Options")
7. Press  or Rec/ button to scroll to the Setup option you want to
change. Press  button to increase the displayed setting.
8. Press Rec/ button to start recording and press again to stop recording.
If entering a Setup option, scroll to the Setup option you want to change.
Press Rec/ button to decrease the displayed setting.
9. Press ENTER button to enter a Setup option. Press ENTER button again
to store the new setting into memory.
Using Thermocouple Input(s)
1. Plug the type K thermocouples into the T1 and T2 input connectors.
2. After one second the thermometer displays the first readings (T1
on upper display, T2 on secondary display). If no thermocouple is
plugged into the selected input or the thermocouple is not properly
connected, the display will show "- - - -". If the temperature being
measured is outside the unit’s valid range, the display will show
“OL” (overload).
Using Infrared Input
1. Purchase optional infrared wand (model 20250-24), shown at right.
2. Plug the IR wand into the T3 (IR) input connector. “T3 - - - -” will
show on screen. If the IR wand is not connected, “T3 - - - -” is not
shown on the screen.
3. Press the SCAN button on the IR wand to begin measuring and the
IR (T3) measurement will be shown on the screen.
Optional IR
wand 20250-24
4
Changing Setup Options
Use the Setup mode to change offset, sample rate, time, clear data logging
memory, and sleep mode settings. The thermometer stores the settings in
its memory.
Option
Menu item
Settings
Offset
T1, T2, T3
T1, T2, or T3 offset
Sample rate
rAt
Sampling of recording
Time setting
tiE
Show the time or set the time
Clear data logging memory
CLR
Clear the memory operation
Sleep mode
SLP
On (sleep mode on) or Off (sleep mode off)
Entering or Exiting Setup Mode
When the thermometer is in Setup mode, the display shows the SETUP
icon. Press and hold Setup button for five seconds to enter or exit the
Setup mode.
Changing a Setup Option
1. Press  or Rec/ button scroll to the Setup option you want to change.
2. Press Enter button to indicate that you want to change this setting.
3. Press  or Rec/ button until the setting you want to use appears on the
display.
4. Press Enter button to store the new setting into memory.
Note: Setup is disabled in the Max/Min/Avg and Recording modes.
Offset Function
The primary display shows the temperature plus the offset
and the secondary display shows the offset. You can store
individual offsets for T1,T2, and T3 (Fig. 1).
Using the Offset to Adjust for Probe Errors
Use the offset option in Setup mode to adjust the thermometer’s readings to compensate for the errors of a
specific thermocouple and IR temperature. The allowable
adjustment range is ±9.0°F or ±5.0°C.
1. Plug the thermocouple into the input connector.
2. Place the thermocouple in a known, stable temperature
environment (such as an ice dry well calibrator).
3. Allow the readings to stabilize.
Fig. 1
4. In the Setup mode, change the offset until the primary reading matches
the calibration temperature. (See “Changing Setup Options")
5
Sample Rate Function
The tertiary display shows the sample rate of the
temperature data recording. When the meter is
powered on, the default sample rate is 1 second.
The tertiary display shows “00 01” in minutes, then
seconds (Fig. 2).
1. Press °C/°F/K button until the value you wish to
change is flashing.
2. Press  or Rec/ button until the setting you
want to use appears on the display.
3. Press Enter button to store the new setting into
memory.
Time Setting Function
Fig. 2
1. While in Setup mode, scroll to the time setting
option screen (Fig. 3).
2. The primary display shows the year. The secondary display shows the month and the day, the
tertiary display shows the hour and minute. In
Fig. 4, the display shows the date and time
“2007-3-30 16:25”. If no adjustment is needed,
press Enter button to exit time setting.
3. Set the time. The adjust order is year, month,
day, hour, minute. Press °C/°F/K button until the
value you wish to change is flashing.
4. Press  or Rec/ button until the setting you
want to use appears on the display.
5. Press Enter button to store the new setting into
memory.
Fig. 3
Clear Memory Operation
Immediately after turning on the meter, the first
value shown is the number of data logging sample
points remaining (from 18,000 to 0). Once the
memory is full, the first value shown will be “FULL”
rather than a number. At this point, you are no
longer able to record until the memory is cleared.
1. Press and hold Setup button for three seconds to
enter the Setup mode. While in Setup mode, the
display shows the SETUP icon.
2. Use the  and Rec/ buttons to scroll to the CLR
memory option screen. The screen indicates the
number of sample points remaining.
6
Fig. 4
3. Press Enter button and “SURE No” will appear on the screen.
4. Press the  or Rec/ button until the display shows “SURE YES”,
indicating the memory will be cleared.
5. Press Enter button to select the “SURE YES” setting and clear the
memory. Data logging capacity now returns to 18,000 sample points.
Auto Power-Off (APO)/Sleep Mode
The meter’s default mode is to automatically shut off after 20 minutes of
non-use. To disable the auto power-off mode, enter the Setup mode.
1. While in Setup mode, press  or Rec/ button to scroll to the SLP
option screen.
2. Press Enter button to display “On.”
3. Use the  or Rec/ button to toggle between “On” (sleep mode on) or
“Off” (sleep mode off).
4. Press Enter button to store the new setting into memory.
Note: Meter defaults back to “On” once meter is powered off.
Displaying Temperatures
1. Press °C/°F/K button to switch between Celsius (°C), Fahrenheit (°F), and
Kelvin (K) temperature scales.
2. Hold or attach the thermocouple(s) to the measurement location. The
temperature reading appears in the primary display.
Note: The display shows "- - - -" when a thermocouple is not connected.
The display shows “OL” (overload) when the temperature being measured
is outside the thermocouple’s valid range.
Hold Function
1. Press HOLD button to freeze the readings on the display. The screen
shows the HOLD icon.
2. Use the DIF/T1–T2–T3 button to toggle between showing the T1 (type K),
T2 (type K), T3 (infrared), and T1–T2, T1–T3, T2–T3 (temperature differentials) measurement in the primary, secondary, or tertiary display.
3. Press HOLD button again to turn off the HOLD function and resume
measuring.
MAX, MIN, and AVG Function
1. Press MAX/MIN button to step through the maximum (MAX), minimum
(MIN), and average (AVG) readings. The elapsed time since entering
Max/Min/Avg mode, or the time at which the minimum or maximum
occurred, appears on the screen.
2. Press and hold the MAX/MIN button for three seconds to exit the
Max/Min/Avg mode and return to normal operation.
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Recording/Data Logging Operation (Meter)
1. Press Power on/off button to turn the unit on. The
first value immediately shown is the number of data
logging sample points remaining (Fig. 5).
2. Press Rec/ button to begin recording; the TYPE K
icon will be flashing to indicate the meter is recording
data measurements.
3. To stop recording, press and hold Rec/ button for
three seconds until the TYPE K icon is no longer
flashing.
4. Note: A maximum of 18,000 sample points is available (Fig. 5). As you log temperature readings, this
value will be lower each time you turn on the meter.
When the memory is full (with 0 sample points
remaining), the first value shown will be “FULL”
rather than a number. Or if you try to record, the
REC icon will flash five times and disappear. At this
point, you are no longer able to record until the
memory is cleared. (See "Changing Setup Options",
"Clear Memory Operation" on pages 6–7.)
Fig. 5. Display shows 18,000
sample points available.
Recording/Data Logging Operation (Software)
1. First install software on PC following the setup wizard (see “Software
Installation” on next page). Once software is successfully installed, the
data logging software icon shortcut will be automatically placed on your
PC desktop.
2. Connect meter to PC via the supplied USB cable.
3. Power the meter on.
4. Open the installed Data Logger Software by double-clicking on the icon
on your PC desktop.
5. In the Data Logger Setting menu, confirm time and select date format,
sampling rate, memory full directions, auto power-off status, and start
method, then select “OK”. You must set these parameters before meter
will record measurements.
a. Note: Manual start method is controlled by user pressing REC
button on the meter. Automatic start method will activate
recording via the software instantly once selected.
6. In manual record mode, press and hold Rec/ button on the meter for
three seconds until the TYPE K icon is flashing, indicating that recording
function has been activated. Upon completion of desired data logging of
measurements, press and hold Rec/ button for three seconds until
TYPE K icon stops flashing, indicating data logging has been deactivated.
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7. To download the data to your PC, select RealTime(R) in the menu bar and
click run. The software screen will display the data being downloaded
from the meter. Upon completion of downloading the data to the PC, the
data results will be displayed graphically.
8. To save the measurement data to your PC, select the “Data List” tab to
open the list of measurements recorded. Select “File” icon from the
menu bar and save data to desired location on your PC. Note: Data will
be saved in an Excel® format that will include all summary information as
captured on the “Data Summary” tab.
9. To print recorded data, simply select the “print” icon on the menu bar.
10. On the menu bar, select HELP to read detailed information on the
capabilities of this software.
Software Installation
1. Insert the CD into the PC.
2. Double-click the set up.exe file to launch the software installation
program.
3. Follow the installation wizard to complete the installation.
4. If the USB driver needs to be updated or driver error message is
received, please go to the folder with driver on the CD and double-click
the file CP210xVCPInstaller.exe to update the driver.
5. Upon successful installation of the software, the software icon shortcut
will be automatically placed on your PC desktop.
9
Specifications
Range
Temperature,
external type K
thermocouple
–328 to 2501°F (–200 to 1372°C)
Resolution
Temperature display
0.1 (<1000) or 1 (≥1000)
Accuracy
T1, T2
±[0.15% reading + 1.8°F (1°C)] above –148°F (–100°C)
±[0.5% reading + 3.6°F (2°C)] below –148°F (–100°C)
T1–T2
±[0.5% reading + 1.8°F (1°C)]
T3 (IR temperature)
±[2.0% reading + 3.6°F (2°C)] above 14°F (–10°C)
±9°F (5°C) below 14°F (–10°C)
T1–T3, T2–T3
±[2.0% reading + 5.4°F (3°C)] above 14°F (–10°C)
±11°F (6°C) below 14°F (–10°C)
Auto power-off
Unit shuts off automatically after 20 minutes to conserve
battery life
Operating temperature
32 to 122°F (0 to 50°C)
Storage temperature
14 to 122°F (–10 to 50°C)
Weight
9.8 oz (280 g)
Dimensions
8" x 3" x 2" (20.1 x 7.5 x 5 cm)
Power
One 9 V battery
Optional Infrared Wand (Model 20250-24)
10
Temperature range
–31 to 1022°F (–35 to 550°C)
Resolution
1 mV per °F/°C
Basic accuracy
±2% or ±4°F (2°C)
Response time
Less than 500 ms
Optical resolution
(Distance-to-Spot ratio)
8:1
Plug diameter
Banana plug: 0.16" (4 mm)
Dimension
61⁄2 " x 2" x 11⁄2 " (16.4 x 5 x 4 cm)
Power
One 9 V battery
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 within the storage range indicated in the
Specifications chart earlier in this manual.
Battery Replacement
When the battery power falls low, the low-battery icon will appear on the
screen. Replace the 9 V battery in the rear battery compartment by removing the cover. Ensure that the cover is securely refastened when finished.
It is recommended that Digi-Sense products are calibrated annually to
ensure proper function and accurate measurements; however, your quality
system or regulatory body may require more frequent calibrations. To
schedule your recalibration, please contact InnoCal, an ISO 17025
calibration laboratory accredited by A2LA.
Phone: 1-866-INNOCAL (1-866-466-6225)
Fax: 1-847-327-2993
E-mail: sales@innocalsolutions.com
Web: InnoCalSolutions.com
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For Product and Ordering Information, Contact:
Toll-Free: 1-800-323-4340
Phone: 1-847-549-7600
Fax: 1-847-247-2929
ColeParmer.com/Digi-Sense
1065DGMAN_20250-19 Rev.1
Toll-Free: 1-800-358-5525
Phone: 1-847-327-2000
Fax: 1-847-327-2700
Davis.com/Digi-Sense
Manual Part No. 00100-58