Vaisala K-PATENTS PR-23 Series, Instruction Manual, Page: 19 / 246

3 Indicating transmitter DTR 9
3 Indicating transmitter DTR
3.1 Indicating transmitter description
The Indicating transmitter DTR is a specialized computer designed to process data
received from one or two sensors. The Indicating transmitter enclosure (Figure 3.1)
contains a front panel with a backlit Liquid Crystal Display (LCD) and a keyboard. The
front panel swings open to give access for connections and service. Knockout pad-
lock provisions are included in the enclosure’s both cover latches for locks to prevent
unauthorized access.
PROCESS INSTRUMENTS PROCESS INSTRUMENTS
POWER
Figure 3.1 The Indicating transmitter enclosure
The sensors send the values of the refractive index n
D
and the process temperature
T to the DTR. The microprocessor system then linearizes the concentration reading
(example in Figure 3.2), and performs an automatic temperature compensation.
10
20
30
40
50
60
70
1.35 1.40 1.45
n
D
BRIX
Figure 3.2 A linearized curve