Digi-Sense 20250-20 User manual

User Manual
THE STANDARD IN PRECISION MEASUREMENT
Professional Thermocouple Thermometer
with Four Type K Inputs, Data Logging,
and Optional Infrared Wand
with NIST-Traceable Calibration
Model 20250-20
Enter
REC
DIF

2
Introduction
The Digi-Sense Professional Thermocouple Thermometer (Model 20250-20)
with Four Type K Inputs, Data Logging, and Optional Infrared Wand offers fast
response and high accuracy. This heavy-duty meter works with up to four type K
thermocouples and one optional infrared probe*. Advanced features include
data logging, USB interface, relative time clock, offset compensation, tempera-
ture 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. Four 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, IR, T3, T4, T1–T2 , T1–IR,
T2–IR, T3–T4, IR–T3, IR–T4; 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 10,000 sampling points
• User-selectable readout in °C, °F, or Kelvin (K)
• 0.1°C / 0.1°F / 0.1 K resolution
• Automatic power-off mode conserves battery life
• Accepts a wide variety of thermocouple type K probes (up to four)
• Optional IR wand available for safe, noncontact temperature measurements

3
Enter
REC
DIF
Meter Description
1. Thermocouple type K input (T1, T2, T3, T4)
2. LCD
3. Enter button
4. Up  button
5. Rec/ button
6. °C/°F/K button
7. HOLD button
8. DIF/T1–T2–T3–T4 button
9. Power on/off button
10. MAX/MIN button
11. Setup /
Backlight button
12. IR input*
*Optional infrared wand (model 20250-24)
must be ordered separately.
12
11
10 7
8
2
4
9
5
1
3
6

4
Display Layout
1. Primary temperature display
2. Tertiary display (IR temperature or recording
time)
3. Min:Sec or Hour:Min display
4. T1 or T3 temperature display
5. Thermocouple type icon
6. Infrared IR TEMP icon (requires Optional IR wand
sku number 20250-24)
7. SETUP mode icon
8. Offset icon
9. Auto power-off icon
10. Low-battery icon
11. T2 or T4 temperature display
12. MAX, MIN, AVG icons
13. Secondary display (T1, T2, T3, or T4 reading)
14. Temperature unit icons (K, °F, °C)
15. Data transmitting to PC icon
16. Recording (data logging) icon
17. Data HOLD icon
15
14
13
12
11
10
1
2
3
4
5
6 7 8 9
17 16

5
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
10,000 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 and hold
MAX/MIN button for three seconds to resume 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. Press DIF/T1–T2–T3–T4 button to toggle between showing the T1, T2, IR,
T1–T2, T1–IR, and T2–IR (differential temperature measurement) in the
primary, secondary, and tertiary display. Press and hold the DIF/T1–T2–T3–T4
button for two seconds to toggle between showing T3, T4, IR, T3–T4, IR–T3,
IR–T4 in the primary, secondary, and tertiary display. Press the DIF/T1–T2–
T3–T4 button again for two seconds to exit.
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 thermocouple(s) into the T1, T2, T3, and T4
input connector(s).
2. Turn meter on. After one second, the thermometer displays the
first reading. If no thermocouple is plugged into the selected
input or if the thermocouple is "open," the display will show "- - - -".
Using Infrared Input
1. Purchase optional infrared wand model number 20250-24
(shown at right).
2. Plug the IR wand into the IR input connector on side of meter;
“IR - - - -” will show on screen. If the IR wand is not connected,
“IR - - - -” is not shown on the screen.
3. Press the SCAN button on the IR wand to begin measuring and
the IR temperature is shown on the screen.

6
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, IR, T3, T4 T1, T2, IR, T3, or T4 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, IR, T3, and T4 (Fig. 1).
Using the Offset to Adjust for Probe Errors
Use the offset option in Setup mode to adjust the ther-
mometer’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.
4. In the Setup mode, change the offset until the primary reading matches
the calibration temperature. (See “Changing Setup Options")
Fig. 1

7
Sample Rate Function
The secondary display shows the sample rate of
the temperature data recording. When the meter is
powered on, the default sample rate is 1 second.
The secondary 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
1. While in Setup mode, scroll to the time setting
option screen. The primary display shows the
year; the secondary display shows the month
and the day; and the tertiary display shows the
hour and minute. In Fig. 3, the display shows the
date and time “2007-08-16 18:55”. If no adjust-
ment is needed, press Enter button to exit time
setting.
2. 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.
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.
Clear Memory Operation
Immediately after turning on the meter, the first
value shown is the number of data logging sample
points remaining (from 10,000 to 0). Once the mem-
ory is full, the first value shown will be “FULL”
rather than a number. At this point, you are no lon-
ger 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 (Fig. 4).
Fig. 2
Fig. 3
Fig. 4

8
Clear Memory Operation (Continued)
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 10,000
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 de-activate 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” (Fig. 5).
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–T4 button to toggle between showing the T1, T2,
IR,T1–T2 ,T1–IR, and T2–IR (differential temperature measurement) in the
primary , secondary, and tertiary display. Press and hold the DIF/T1–T2–
T3–T4 button for two seconds to show T3, T4, IR, T3–T4, IR–T3, and IR–
T4 in the primary, secondary, and tertiary display. Press and hold the
DIF/T1–T2–T3–T4 button again for two seconds to return.
3. Press HOLD button again to turn off the HOLD function and resume
measuring.
Fig. 5

9
Viewing the MAX, MIN, and AVG Readings
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 display.
2. Press and hold the MAX/MIN button for three seconds to exit the
Max/Min/Avg mode and return to normal operation.
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. 6).
2. Press Rec/button to begin recording; the REC icon
will be appear to indicate the meter is recording data
measurements.
3. To stop recording, press and hold Rec/button for
three seconds until the REC icon is no longer shown.
4. Note: A maximum of 10,000 sample points is avail-
able (Fig. 6). 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 7–8.)
Recording/Data Logging Operation (Software)
1. First install software on PC following the set up 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 thermometer to your 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 instrument. Automatic start method will activate
recording via the software instantly once selected.
Fig. 6

10
Recording/Data Logging Operation (Software) continued
6. In manual record mode, press and hold Rec/button on the meter for
three seconds until REC icon is indicated on the screen, indicating that
recording function has been activated. Upon completion of desired data
logging of measurements, press and hold Rec/button for three seconds
until REC icon disappears from the screen, indicating data logging has
been deactivated.
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.

11
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, T3, T4 ±[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, T3–T4 ±[0.5% reading + 1.8°F (1°C)]
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–IR, T2–IR, IR–T3,
IR–T4
±[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)
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

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
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 remov-
ing 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: [phone]
E-mail: [email protected]
Web: InnoCalSolutions.com
Manual Part No. 00100-69
1065DGMAN_20250-20 Rev.1