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User Manual
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Thermohygrometer with Single
Type K Input and Superheat Function
with NIST-Traceable Calibration
Model 20250-12
THE STANDARD IN PRECISION MEASUREMENT

Introduction
The Digi-Sense Thermohygrometer (Model 20250-12)
with Single Type K Input and Superheat Function offers
fast response and high accuracy. This meter is both a digital thermohygrometer and a valuable HVAC diagnostic
tool—it measures humidity, dew point, wet bulb, dry
bulb, temperature, plus target superheat (TSH) and target
evaporator exit temperature (TEET). Meter also features
Min/Max/Hold readings and automatic power-off, and
accepts a wide variety of thermocouple probes. The
instrument is fully tested and calibrated to NIST-traceable
standards. Careful use of this meter will provide years of
reliable service.
Unpacking
Carefully unpack the instrument and accessories from
shipping package. Check individual parts against the list
of items below. If anything is missing or damaged, please
contact Cole-Parmer immediately.
1. Meter
2. One type K flexible probe
3. Carrying pouch
4. Three AAA batteries
5. User manual
6. NIST-traceable calibration report with data
2

Meter Description
1. Thermocouple type K input
2. Thermistor temperature sensor (internal)
3. MODE button
4. ENTER button
5. OUTPUT button
6. °C/°F /
7. SENSOR button
8. MAX/MIN/HOLD button
9. Power On/Off button
10. LCD
11. Humidity sensor (internal)
12. Battery cover
Backlight button
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3
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9
2
11
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7
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12
3

Display Functions
1. Low-battery indication
2. Measurement icons (RH, DP, WB, DB)
3. °C/°F icons for upper display
4. Indoor (ID) / Outdoor (OD) icons
5. Upper measurement display of humidity,
dew point, wet bulb, dry bulb, temperature
6. MIN / MAX icons
7. Humidity measurement (%RH) icon
8. HOLD icon
9. Thermocouple (T/C) and Thermistor (NTC) icons
10. MODE select icons (NORM, TEET
11. Auto power-off (APO) indication
Lower measurement display of target superheat
12.
and target evaporator exit temperature
13. °C/°F icons for lower display
, TSH)
2
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9
10
12
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3
4
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