K-Patents PR-03 - Manual (Page 15)

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3 Indicating transmitter (IT-R) 9
3 Indicating transmitter (IT-R)
3.1 Indicating transmitter description
The indicating transmitter (abbr. IT-R) is a small, specialized computer designed to process data received
from the sensor. The Indicating transmitter enclosure (see Figure 3.1) contains a front panel with a Liquid
Crystal Display (LCD) and a keyboard. The IT-R’s microprocessor system and the power supply are hidden
under the front panel that swings open for service. Knockout padlock provisions for locks are included in
the enclosure’s both cover latches to prevent unauthorized access.
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K-PATENTS
PROCESS INSTRUMENTS
Figure 3.1 The Indicating transmitter enclosure
The IT-R receives from the sensor data that describes the optical image and gives the process temperature.
It then displays the optical image (Figure 1.3) and implements an image analyzing algorithm (Figure 3.2),
which identifies the exact position of the shadow edge (Figure 2.2). Finally, the microprocessor system
linearizes the concentration reading (example in Figure 3.3), and performs an automatic temperature com-
pensation.
Raw data
Curve fitted to the data
Figure 3.2 Image analyzing algorithm
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BRIX
Figure 3.3 A Brix diagram
The IT-R output signals are a 4-20 mA concentration signal and a serial output signal, RS232 or RS485
alternatively, which enables connections to for example a PC (See Section 3.2.3).
In the IT-R there are also two built-in signal relays on the power supply card. These signal relays can
be configured to any relay function except preconditioning or wash control (see Section 5.7, “Configuring
relays”).