ASL INTERCOM CTR5000, Руководство пользователя

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CTR5000 Operating Instructions
16 ASL operating instructions, model CTR5000
1.4 Principles of measurement
See appendix 6 for a detailed description.
1.5 Temperature measurement
When using PRTs, the relationship between resistance and temperature varies slightly from
one PRT to another. Therefore, no matter how accurately the CTR5000 measures the PRT
resistance, if the relationship between resistance and temperature for a particular PRT is not
known, accurate temperature measurement is not possible.
The CTR5000 uses PRT calibration data to overcome this problem and calculates the
temperature from conversion functions using calibration data stored in internal non-volatile
memory. This method enables the CTR5000 to convert ratio to temperature, uniquely for each
sensor used. It is very important, therefore, that a sensor is used with the probe’s coefficients
correctly entered into the instrument. The CTR5000 uses the standard DIN90 conversion
method when specific probe calibration data has not been entered. Temperature conversion
occurs in real-time.
Note
Always check that the coefficients are correctly set for
the probe being used. Failure to do so, will almost
certainly lead to incorrect measurements.
System accuracy is a combination of the Bridge’s accuracy in measuring the probe’s
resistance ratio and the calibration uncertainty placed on the reference resistor and PRTs by
the calibrating laboratory.
When calibrated PRTs are used with the CTR5000, either with or without switchboxes, the
calibration data can be entered via the keypad on the front panel, and is stored in internal
memory. Stored PRT calibration data may also be reviewed.
1.6 Measurement units
Units can be set on a per probe basis (probes are assigned to channels). When a new
channel is selected, the CTR5000 will check to see if a probe is assigned to that channel. If it
is, the programmed probe’s units will be used (initially) - this does not prevent the units from