Comark C21 Bedienerhandbuch Seite 2

Low Alarm – the display will show 'LOAL'
Use the countdown timer and hold buttons to select or de-
select low alarm, then select the required low alarm value.
Auto Power OFF – the display will show 'AOFF'
Use the countdown timer button and the hold button to scroll
between the available options of 3, 10, 30 minutes or none.
Clock Alarms – the display will show AL 1, followed by
AL 2 and AL 3
Three Clock Timer Alarms can be set. Use the countdown
and hold buttons to select or deselect Clock Alarm, and then
to select the required time. Note that on instruments with no
AM or PM indicator it will show the change by the way the
time changes over midnight or noon. At midnight the display
will change from 11:59 to 0:00, indicating AM, and at noon the
display will change from 11:59 to 12:00, indicating PM.
Repeat for AL 2 and AL 3.
Resolution – the display will show 'HrES'
Use the countdown and hold buttons to select or de-select
temperature display in high resolution 0.1° or low resolution
1°.
Care of the Thermometer
C20 series thermometers are dust and splashproof and will
withstand harsh environments. Use a damp cloth or warm
soapy water to remove deposits and prevent them from
hardening or becoming sticky. Do not use solvent-based
cleaners or methylated spirit, etc.
Caution: Do not place any C20 series thermometers in a
dishwasher.
Specifications Continued
Ambient Temperature Range
-20°C (-4°F) to +50°C (122°F) operating
Display 4 digit, 12.5 mm LCD
Battery Two Type I.E.C. LR6 Size AA
Battery Life (continuous) Up to 14000
hours with thermistor probes
Up to 7000
hours with thermocouple probes
EMC Emission Tested to EN61326-1
Criteria B Performance
Dimensions
Length 152mm/6 inches
Width 58mm/2.3 inches
Depth 22/27mm/09./1.1 inches
Weight 178g/6.3 ozs
Changing the Batteries
The symbol BAT appears on the display when the battery
voltage has reduced. Battery replacement is recommended at
this time.
To replace the battery, remove the battery cover retaining
screw on the rear of the instrument, using the correct size
screwdriver. Remove the two cells, and replace with alkaline
cells only. Be careful to observe the correct polarity. Take
care not to over-tighten the screw when refitting the cover.
Note: The C20 series thermometers will not work if the battery
compartment is incorrectly fitted or missing. In this instance
the display will show 'OPEn'. Please note the small pip on the
inside of the battery cover, which must fit into the hole
provided in the back of the case.
Specifications for C20 Series Thermometers
Measurement
Thermistor 10 K Ohms unicurve
Thermocouple type T and K
6-pin Lumberg and Sub-Min Connectors
Measurement Range
-50°C(-58°F) to +150°C(302°F) Thermistor
-200°C(-328°F) to 400°C(752°F) Type T
-200°C(-328°F) to 600°C(1112°F) Type K
Scales °C and °F
Displayed Resolution 0.1° > -100°
 -100°
1°
Instrument Accuracy
Thermocouple 0.1% ± 0.2°C(0.4°F) full range
@ 23°C Ambient
Thermistor ±0.3°C (±0.6°F)
System Accuracy 0°C (32°F) to 70°C (158°F)
±0.5°C (±0.9°F)
-25°C (-13°F) to 100°C (212°F)
@ 23°C Ambient
Temperature Coefficient
Thermistor less than 0.005°C/°C (0.01°F per °F)
Thermocouple less than ± 0.01 % of reading ±0.02 °C per °C
(±0.04°F per °F) change from 23°C
5
4
Appendix 1 – C20 Series Model Range Options
Models C21 C22
Part No. C21 C22
Options
Countdown

Timer

Data Hold
Real Time

Clock
Clock Alarms -
Scale

Selection
High Alarm -
Low Alarm -
High

Resolution
Type T -
Type K -

Thermistor
Connector* L

Auto Off

Splashproof
* L – Lumberg
S – Sub-Miniature
7
6
C22 T C28 K
C26
Type Type
C22F C26 C28F
   
   
   

- - -
   
 
- -
 
- -
   
  
-

- - -
 
- -
L L S S
   
   