WIKA CPT6010, Руководство по эксплуатации

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CPT6010 Operating Instructions 17
Digital Pressure Transducer
CPT6010
6. Operation
The pressure to be measured is applied to the 1/4 NPT fitting on the CPT6010.
!
Caution
Avoid excessive overpressure to the sensor! Externally mounted relief
valves to provide overpressure protection are available from Mensor as
optional devices, and are highly recommended for very low pressure
transducers.
A CPT6010 samples the pressure every 20 milliseconds (50 Hz).
User programmable exponential filtering is applied to pressure readings in order to minimize at or
near static pressure noise. The filter value can range from 0 (filter OFF) to 99 (maximum filtering).
For any positive filter value, the filter is disabled when the pressure change between consecutive
readings is greater than 0.02% full scale. However, each pressure change of 0.02% FS, or less, be-
tween consecutive readings will apply the exponential filter to the output pressure value to smooth
out the readings.
The user can reset the zero and span values via the serial port in order to calibrate the instrument,
or the user can change any of several other operating values. The user can also query the device
for its current pressure reading, or to find the current settings for other parameters.
The serial port is set at the factory for either RS-232 or for RS-485 serial operation according to the
customer’s instructions. This section of the manual provides information on the serial port configu-
ration, explains the command conventions used in this manual, and lists the common commands
and queries which are recognized by the CPT6010.
6.1 Multiple Turndown Devices
The availability of two different turndown ranges in one device has many obvious benefits, but
certain issues should be noted for application of devices with multiple ranges. An important factor
to remember is that the two ranges are completely discrete. Consequently, any and all parameters
can be set to different values between the two turndown ranges. The independence of the two
ranges has a specific impact on application of the transducer that is detailed below and in section
6.3, CPT6010 Address.
6.1.1 Filter Effects of Multiple Turndowns
An area of concern when using devices with multiple turndowns is the effect of the exponential
filter on the reading output. In the case that a user is emulating an auto-ranging scheme by quickly
switching between turndown ranges of one device, the exponential filter can skew the reading out-
put of the device immediately after a switch is made. The reason for this skewing is the persistence
of previous pressure samples in the reading buffer and their use in the filtering scheme.