Technical Data - Delta OHM HD 92188 Manual Del Usuario

HD 9218 DIGITAL
MICROPROCESSOR THERMOMETER
FOR THERMOCOUPLE TYPE K
This is a very compact portable instrument. Its high technological featu-
res are accompanied by a pleasing design.
With its range of interchangeable probes, it is an indispensable instru-
ment for measuring temperature in the fields of maintenance,
heating/air-conditioning, laboratories, food and agriculture and all other
sectors where temperature measurements must be precise, fast and
repeatable.
The instrument stores the MAX and MIN values, the reading can be in
°C or °F. The calibration is managed by the keyboard.
CHARACTERISTICS
- Instrument measuring range: -200°C...+1370°C
- Resolution: 0,1°C (0,1°F) from -200°C to +200°C
above 1°C or 1°F
- Automatic change of scale
- Instrument switches off automatically after 8 minutes (the auto power
off function may be disactivated)
- Temperature measurement with a thermocouple type K
- High precision
- Range of probes available for measurements by immersion, surface
contact and penetration
- Low battery charge warning light
- Battery power supply
- Calibration with storage of the calibration data in the memory
Instrument calibration - you can choose between the manufacturer's
calibration - which cannot be changed - and the personal one - which
can be changed
Calibration of instrument alone
Calibration of instrument and respective probe.

TECHNICAL DATA

- K type thermocouple input
- Measuring range: -200°C...+1372°C
-328°C...+1999°C
- Resolution: ≤ 199.9°C (°F) = 0,1°C (0,1°F)
≥ 200°C (200°F) = 1°C (1°F)
- Precision of instrument alone:
From 0°C to 200°C = ±0,5°C. From +200°C to full scale and from
-0,1°C to -200°C = ±2°C
- Temperature coefficient from -5°C to 50°C: 0°C/°C from 18°C to 25°C
0,01 °C/°C outside this range.
- Conversion frequency: 1 second
- The total precision of the instrument plus the chosen measuring probe
is given by the sum of the instrument error plus the error of the chosen
probe
- Instrument working temperature: -5°C...+50°C
- Storage temperature: -20°C...+60°C
- Relative humidity: 0...90%R.H.
1
- Display: LCD display with 3
symbols
- Functions:
Autorange, storage and updating of MAX and MIN, reading in °C and
°F. Calibration managed by the keyboard with storage of the calibra-
tion data in the memory
- Power supply: 9V battery, IEC 6LF22, zinc/carbon battery life approx.
150 hours
- Low battery charge warning light
- Device for activating or disactivating the auto power off function
- Input standard miniature connector for thermocouples
- Case: ABS Bayer NOVODUR, grey 7553CF
- Dimensions: instrument 42x185x23 mm - weight 130 grams
- Dimensions instrument complete with carrying case 370x140x60 mm -
weight 500 grams.
-328°F...+1999°F
⁄ digit, height 8 mm MAX, MIN, °C and °F
2
ORDER CODE
HD 9218: composed by instrument complete with zinc/carbon battery, instructions
and carrying case.
THE PROBES MUST BE ORDERED SEPARATELY.
Any type K thermocouple probe, made by Delta Ohm or by other manufacturers
may be connected to the instrument, as long as they are fitted with a standard
miniature connector.
- Thermocouple:
Temperature measurement device composed of two homogeneous metal ther-
moelements, different and insulated one from the other in their whole length.
The two thermoelements are soldered together at one end - which is called a
measuring junction or, sometimes, warm junction, and are connected to a mea-
surement circuit of EMF. The connection area between the thermocouple and
the measuring circuit is called a reference junction or, sometimes, cold junction.
When there is a difference of temperature between the measuring junction and
the reference junction, the thermocouple produces an EMF depending on the
difference of temperature (Seebeck effect).
- Thermoelement:
One of the two wires which form the thermocouple. In each thermocouple you
can distinguish the thermoelement with positive electric sign from the thermoe-
lement with negative electric sign according to the direction (polarity) of the
EMF produced by the thermocouple.
- Thermoelectric power:
This is the increase of EMF produced by the thermocouple when the reference
junction is kept at a constant temperature and the temperature of the measuring
junction is increased by 1°C.
- Measuring junction (warm junction):
This is the end of the thermocouple where the two thermoelements are solde-
red one to the other; it is the sensitive thermical side of the thermocouple.
- Reference junction (cold junction):
This is the isothermal connection area between the thermocouple and the mea-
surement circuit.
- Electromotive force (EMF) of the thermocouple:
This is the difference of electric potential which is measured at the open termi-
nals of the thermocouple when there is a difference of temperature between the
measuring junction and the reference junction.
- Identification of the thermocouples:
Type of thermocouple
S Platinum - 10% Rhodium vs. Platinum
R Platinum - 13% Rhodium vs. Platinum
B Platinum - 30% Rhodium vs. Platinum - 6% Rhodium
J Iron vs. Copper - Nickel
T Copper vs. Copper - Nickel
K Nickel - 10% Chrome vs. Nickel - 6% Aluminium
E Nickel - 10% Chrome vs. Copper - Nickel
- The MAX temperature limits which are recommended for the K thermocouple
and the relative dimensions of the wires are indicated in the prospectus. These
limits are suitable for protected thermocouples, that is for thermocouples inser-
ted in ceramic insulators in metallic or ceramic protection sheathes which are
closed at one end. The indicated temperature limits and the respective diame-
ters of the thermoelements are such as to allow a satisfactory life of the thermo-
couple in continuous operation.
- Working temperature limits of the thermoelements:
K Thermocouple
- Tolerance:
The tolerance of a thermocouple type corresponds to the max. accepted devia-
tion of the EMF, of any thermocouple of such type with reference junction at
0°C. Tolerance is expressed in degrees Celsius, preceded by the mark ±.
Tolerance per cent is given by the ratio between the tolerance expressed in
degrees Celsius and the temperature of the measuring junction, multiplied by
one hundred. The thermocouples which fulfil the standards must respect one of
the two following tolerance degrees, the values of which are indicated in the
table.
G I (special tolerances)
G II (standard tolerances)
The tolerances refer to the operation temperature for which the thermocouple is
intended according to the diameter of the thermoelements.
- Thermocouple tolerances:
Type of °C range
thermocouple
K 0 .. 1250
K** -200 ..... 0
* Refers to the higher limit of the two options. For example:
for the thermocouple type K tolerance G II, at 200°C the tolerance per cent
±0,75% is equivalent to ±1,5°C. Therefore the limit ±2,2°C is the valid one.
At 600°C, instead, the per cent tolerance is equivalent to ±4,5°C, so this is
the limit to use.
** Tolerances which can be obtained on request. The thermocouples which ful-
fil the limits for temperatures higher than 0°C do not necessarily fulfil the
limits for the range below 0°C.
Material of the type of thermocouple
Diameter of the wires in mm.
3.2 1.6 0,8 0,5
Max temperature limit °C
1250 1090 980 970
G I* G II*
±1,1°C or ±0,4% ±2,2°C or ±0,75 %
– ±2,2°C or
0,3
870
±2 %