Omega Engineering HH-21 User manual

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TABLE OF CONTENTS
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Difference Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Manual Addenda. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Unpacking and Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Battery Installation/Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Memory Backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operation with Rechargeable Battery . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operating Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1. Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2. Display Annunciators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3. Function Keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Service Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1. Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2. Disassembly Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3. Mechanical Parts Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4. Component Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5. Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6. Schematic Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Limitation of Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Statement of Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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GENERAL INFORMATION
This manual provides information on the use of three digital handheld ther-
mometers. Functional features both common and unique to each model are
described.
All three models are microprocessor based, and provide accurate and
reliable operation. They function with the most popular thermocouples; types
K, J, and T. A variety of features in these projects enhance their versatility,
while simplifying operation.
It is recommended that you read this manual thoroughly, especially the
sections on safety, prior to operating these instruments.
SPECIFICATIONS
THERMOCOUPLE INPUTS: 2 (T1, T2) miniature TC connectors.
Accepts male miniature and subminiature TC connectors.
THERMOCOUPLE TYPES: K, J, T
READOUT: T1, T2, T1-T2, and SCAN (T1, T2, T1-T2).
ACCURACY: (18°C to 28°C ambient, 2 years, excludes thermocouple error).
REPEATABILITY: ±0.2°C typical for 1 week at constant ambient temperature.
TEMPERATURE COEFFICIENT: 18°C to 28°C; included in accuracy specification.
From 0°C to 18°C, and 28°C to 50°C; less than ±(0.02% rdg + 0.1°C)/°C.
ENVIRONMENTAL LIMITS FOR OPERATING: 0°C to 50°C, less than 80% relative
humidity (R.H.) up to 35°C; reduce R.H. limit by 3%/°C from 35°C to 50°C.
ENVIRONMENTAL LIMITS FOR STORAGE: –35°C to 60°C, less than 90% relative
humidity (R.H.) up to 35°C; reduce R.H. limit by 3%/°C from 35°C to 60°C.
INPUT CURRENT: 50 nA typical.
READING RATE: (T1, T2, T1-T2); 1 reading/second typical, all parameters.
TC Extended Temp.
Type Range Resolution Accuracy (T1, T2) Accuracy (T1-T2) Range Acc’y (T1, T2), Typ.
K –200°C to 1372°C 0.1/1°C ±(0.1% rdg + 0.6°C) Acc’y (T1) + Acc’y (T2) –200°C to –250°C, ±(3°C)
–328°F to 2502°F 0.1/1°F ±(0.1% rdg + 1.0°F) Acc’y (T1) + Acc’y (T2) –328°F to –418°F, ±(5°F)
J –210°C to 760°C 0.1/1°C ±(0.1% rdg + 0.6°C) Acc’y (T1) + Acc’y (T2) —
–346°F to 1400°F 0.1/1°F ±(0.1% rdg + 1.0°F) Acc’y (T1) + Acc’y (T2) —
T –200°C to 400°C 0.1/1°C ±(0.1% rdg + 0.6°C) Acc’y (T1) + Acc’y (T2) –200°C to –250°C, ±(3°C)
–328°F to 752°F 0.1/1°F ±(0.1% rdg + 1.0°F) Acc’y (T1) + Acc’y (T2) –328°F to –418°F, ±(5°F)

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MAXIMUM COMMON MODE VOLTAGE: 42V peak to earth.
POWER: 9 volt transistor battery (NEDA 1604).
BATTERY LIFE, CONTINUOUS: 50 hrs typical, carbon-zinc; 100 hrs typical, alkaline;
200 hrs typical, lithium; 15 hrs typical, Ni-Cd (rechargeable).
BATTERY INDICATOR: Display indicates BAT when less than 10% of life remains.
DISPLAY: 5 digit LCD, 0.4" height. Polarity indication, and decimal point.
Annunciators
• Readout Parameter: T1, T2, T1-T2, SCAN
• Record Parameter: MIN or MAX (when viewing recorded data).
• Readout Scale: °F, °C
• TC Type: K, J, T
• Hold (when activated)
• Reading Trend: up-arrow for increasing readings, down-arrow for decreasing
readings. Both arrows on for stable reading.
• Record MIN/MAX readings for T1, T2, and/or T1-T2; Flashing annunciator indi-
cates data being collected. Steady annunciator indicates data available, but not
being up-dated.
KEYPAD: 9 momentary switches with tactile feedback select;
• Power ON/OFF
• Readout: T1, T2, T1-T2, or SCAN
• TC type: K, J, T
• Readout scale: °F/°C
• Resolution: 0.1°/1°
• Display Hold
• Record MIN/MAX
• View MIN/MAX
• Stop recording MIN/MAX (first keystroke), clear recorded MIN/MAX (second
keystroke)
POWER OFF CONFIGURATION RETENTION: Instrument retains last selected;
• Readout: T1, T2, T1-T2, SCAN
• TC type: K, J, T
• Resolution: 0.1°/1°
• Scale: °F/°C
DIAGNOSTICS: Display codes indicate the following conditions:
• Low Battery: ‘BAT’
• Open Thermocouple(s): ‘OPEN’
• Invalid Keypad Entry: Momentary ‘E-1’
• Temperature Reading exceeds TC Rating: ‘E-2’
• Internal Hardware Fault: ‘E-3’ (consult factory)
• LCD Test: During power-up, all segments/annunciators turned on momentarily.
ELECTROMAGNETIC COMPATIBILITY: Add ±0.5% of range to accuracy specific-
tions for RF fields up to 1 volt/meter. Accuracy not specified for fields greater than
1 volt/meter.
DIMENSIONS, WEIGHT: 7.0" x 2.9" x 1.1". Net weight 10 oz.

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DIFFERENCE SPECIFICATIONS
MODEL HH-21:
THERMOCOUPLE INPUTS: 1
DISPLAY: 5 digit LCD, 0.4" height. Polarity indication, and decimal point.
Annunciators
• Readout Scale: °F, °C
• TC Type: K, J, T
• Hold (when activated)
KEYPAD: 5 momentary switches with tactile feedback select;
• Power ON/OFF
• TC type: K, J, T
• Readout scale: °F/°C
• Resolution: 0.1°/1°
• Display Hold
POWER OFF CONFIGURATION RETENTION: Instrument retains last
selected;
• TC type: K, J, T
• Resolution: 0.1°/1°
• Scale: °F/°C
MODEL HH-22:
THERMOCOUPLE TYPES: K, J

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FEATURES
• Temperature trend indication (rising, falling, or stable)
• Full range resolution of 0.1 degree
• Work with thermocouple types K, J and T
• Kpad selectable °F or °C
• Two probe inputs (for two point temperature measurements)
• Calculates and displays temperature difference between the two probe
inputs
• Maximum and minimum temperature storage
• Dust proof, splash proof, drop proof construction
• Built-in tilt stand/hanger for bench use or hands free field measurements
• User friendly function programming
• Performs self diagnostic test and displays error readout
• Retains function settings, even when turned off
• Low battery and open sensor indication
• Input data scan and display hold modes
MANUAL ADDENDA
Improvements or changes to this manual will be explained on an addendum
included with the instrument. All change information should be incorporated
immediately into the appropriate places in the manual.
UNPACKING AND INSPECTION
Each instrument is inspected both mechanically and electrically before ship-
ment. Upon receiving your instrument unpack all items from the shipping
container and check for any obvious damage that may have occurred during
transit. Report any damage to the shipping agent. Retain and use the origi-
nal packing materials if reshipment is necessary.

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SAFETY INFORMATION
SAFETY SYMBOLS AND TERMS
The symbol on the instrument denotes that the user should refer to the
operating instructions.
The WARNING used in this manual explains dangers that could result in
personal injury or death.
The CAUTION used in this manual explains hazards that could damage
the instrument.
SAFETY PRECAUTIONS
WARNING
These instruments are intended for use by qualified per-
sonnel trained in the safe operation of electronic testing
equipment. Read the instruction manual thoroughly before
using, to become familiar with the instrument’s operations
and capabilities.
WARNING
Do not touch a temperature probe sheath when measuring
excessively high or low temperatures, or toxic substances.
WARNING
Do not attempt to measure temperatures beyond the range
of the probe being used. Probe damage or personal injury
could result from exceeding a probe’s maximum tempera-
ture rating.
WARNING
The American National Safety Institute (ANSI) states that a
shock hazard exists when probes or sensors are exposed
to voltage levels greater than 42VDC or 42V peak AC. Do
not use this instrument where voltages at the measure-
ment surface exceed these levels.
▲▲
!

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WARNING
Do not substitute a metal part for the nylon screw in the
rear case. Doing so will degrade electrical isolation of the
case.
WARNING
The battery is accessible through a cover on the back of
the instrument. To avoid electrical shock hazard, discon-
nect all temperature probes and sensors and turn the unit
off before removing the cover.
WARNING
Never use this instrument or any probe or sensor inside a
microwave oven.
CAUTION
Avoid making sharp bends in probe or sensor lead wires.
Bending lead wires at a sharp angle can damage the wire
causing probe failure.
CAUTION
When using both thermometer inputs, and a voltage differ-
ential exists between the two measurement points, at least
one probe should be electrically insulated. If not, ground-
loop current can flow through the thermocouple leads
causing measurement error or instrument damage.

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BATTERY INSTALLATION/REPLACEMENT
A 9V battery is supplied with the instrument but not installed. Read the fol-
lowing installation instructions before attempting to install or remove the bat-
tery.
WARNING
Turn the unit off and disconnect any input connections
before replacing the battery. Put the cover back into place
on the battery compartment before resuming use of the
instrument.
1. Remove the cover from the battery compartment by sliding it off in
the direction of the arrow located on the battery cover.
2. Remove the old battery.
3. Place the new battery in the battery compartment. Be sure to
observe proper polarity.
4. Re-install the battery cover before resuming use of the instrument.
NOTES:
• Less than 10% of battery life remains when the BAT annun-
ciator turns on.
• If the instrument is going to be stored for a long period of time
or in a high temperature environment, remove the battery to
prevent leakage damage.
• After a new battery is installed, allow approximately 30 sec-
onds for reading stabilization the first time the instrument is
turned on.
Figure 1. Battery Installation