Carel DLOGNTC015 Manual De Utilización página 25

Periodical verification procedures
Carel certifies, with a paper included in the packaging ("Calibration certificate"), that the Datalogger was calibrated
in the factory. However, according to normative laws, a periodical verification of the instrument is necessary in
order to guarantee the reliability of the recordings. Whatever the outcome of the verification, this one must be
noted down and kept. Carel reports an example of forms (see enclosures A, B and C). Carel advises to follow
the periodical verification procedures here enclosed which generally follows verification procedures establi-
shed by the normative law relevant to the Carel Datalogger. For more details, please refer to the laws in force
in your Country.
Measurement instrument
Direct comparison by using a measuring apparatus, periodically tested with thermometer and multimeter
checked and certified by SIT. Since the Datalogger is guaranteed with a precision of ±1.0°C, the error of the
standard thermometer must be lower than ±0.2°C, resolution 0.1.
Preliminary operations
• Make sure the Datalogger is not near devices that cause electromagnetic interferences.
• Make sure the probes, and the relevant cables, are not placed immediately near other cables of electronic
and electric devices.
• Clean the probe.
• Check the connections to the Datalogger, by making sure the Datalogger is carrying out the measurement
of the temperature.
Performance of the verification
• Verification should be carried out around the working temperature, keeping it constant as much as possible.
It is absolutely necessary to avoid excessive changes of the equilibrium of the system, once the verification
stage has been started (e.g. open the door, to allow the compressor to start, switch on the light, ....).
• Place the calibrated thermometer as near as possible to the probe to be verified, striving for an acceptable
thermal coupling (e.g. by constraining the two - probe and Datalogger - sensors , with thermoconductive
materials such as copper).
• Note down periodically the temperature simultaneously read by the precision instrument and the Datalogger,
noting down possible modifications of the state of the system (e.g. stopped compressor, open door etc., so
as to point out time response, delay time, heat radiation, etc.).
Results of the verification
If the difference between the value measured by the Datalogger and that of reference is:
• Lower than or equal to ±0.8°C , the outcome is acceptable.
• Ranging from -1.0°C to -0.8°C and from 0.8 to -1.0°C, the outcome is acceptable, but the instrument must
be verified within 6 months.
• Lower than - 1.0°C and higher than 1.0°C: the outcome is negative.
If the verification has a negative outcome, you can try to replace the Datalogger probe. If the Datalogger with
a new probe proved again to be out of precision, the instrument has to be returned to Carel for a new calibration.
Important
The enclosures A and B of the manual are the masters to be photocopied at each verification. The copies of
the enclosures A and B must be filled in and kept and represent the verification report of the Datalogger
instrument.
The enclosure °C is the life-cycle sheet. It collects the data of each verification report.
These documents do not replace the calibration certificate issued by Carel.
Carel can carry out, on request, the periodical verification of the Datalogger for the customers.
Please contact Carel after sales service.
APPENDIX
44
Identification of the body charged
for verification
Sent to: ...............................................................
Means of verified
Measurement:
.....................................................
Description:
.........................................................
This report includes «...........» page(s) and «............» annee(s)
N.B. This document may not be used in place of a calibration certificate.
ENCLOSURE A
Verification report
n°:..................................
Type: ........................................................
Serial No: .................................................
Verification date: .....................................
Manager: ................................................
Name: ......................................................
Signature: ................................................
45