Measuring Cell Operation - Siemens SITRANS P DS III Operating Instructions Manual

Description
3.6 Functional principle
● The digital signal is then converted in a digital-to-analog converter
current of 4 to 20 mA. A diode circuit provides reverse voltage protection.
● You can make an uninterrupted current measurement with a low resistance ammeter at
the connection
● The measuring cell-specific data, electronics data and parameter assignment data are
saved in two EEPROMs
to the electronics.
Operation
● The buttons
● If you have a device with a display
device messages.
● The basic mode settings can be changed with a computer and HART modem
PDM.
3.6.3

Measuring cell operation

Destruction of the seal diaphragm
Danger of injury or damage to device
If the seal membrane is destroyed, the sensor may also be destroyed. If the seal
membrane is destroyed, no reliable measured values can be output.
Hot, toxic and corrosive process media can be released.
• Ensure that the material of the device parts wetted by the process medium is suitable for
• Make sure that the device is suitable for the maximum operating pressure of your
• Define maintenance intervals for regular inspections in line with device use and
In the following sections, the process variable to be measured is called general inlet
pressure.
Overview
The following modes of operation are described:
● Gauge pressure
● Absolute pressure
● Differential pressure and flow rate
● Level
26
⑩
.
⑧
can be used to call up individual functions, so-called modes.
WARNING
the medium. Refer to the information in Technical data (Page 175).
system. Refer to the information on the nameplate and/or in Technical data (Page 175).
empirical values. The maintenance intervals will vary from site to site depending on
corrosion resistance.
⑥
. The first memory is linked to the measuring cell, the second
⑨
, you can use it to track the mode settings and other
⑤
into the output
SITRANS P DS III with HART
Operating Instructions, 06/2013, A5E00047092-09
⑦
via