Honeywell Enraf VITO, Instruction Manual

Page: 32 / 52

Average temperature measurement with MPT / RTD
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Instruction manual VITO Page 30
Refer to figures 4.1 and 4.2
Item
Name Description
W2
= Protection level 2 Enter protection level 2
TD
= Temperature dimension One character; either ‘C’ or ‘F’. Default set to C.
C : degrees Celsius
F : degrees Fahrenheit
Both dimensions have the same format.
MT
= Element type Three ASCII characters. Selects the element type connected to
the 762 VITO MRT Interface. For 1 – 3 RTD’s and MPT probe,
set this item to: ‘ SPL ’ (Pt100 large);
range : -200
÷
+250
°
C (-328
÷
+482
°
F)
MN = Number of elements Two ASCII digits. This item specifies the number of elements
of the MPT probe.
•
01 through 03 means RTD spot in a 3 wire connection
•
04 through 14 means an MPT probe.
MO
= Temperature element offset Format according to item
LD
. The offset represents the distance
from the tank zero level to the lowest position of the MPT probe.
In case of the RTD spots this item should be left at 0.
Note:
In case of ullage measurement, distance MO is taken from
the upper reference point.
J0 – JD
= RTD element position. Format according to item LD . In case of the RTD spots items
J0 .. J2 represent the distance from tank zero level to the RTD
spot.
In case of a MPT probe items
J0 .. JD represent the distance
from the bottom of the probe (nearest to tank zero level) to the
RTD elements. Refer to the description above to obtain the
values for
J0
..
JD
.
Note:
Only enter as much element positions as specified by the number
of elements, starting from
J0 (see item MN ).
MI
= Switch hysteresis Format according to item
LD
. The distance
MI
is a hysteresis
around the switching point of the temperature elements.
MP = Product immersion depth Format according to item LD . The distance MP specifies the
minimum required liquid level above a spot before it is selected
for the average product temperature calculation
MG = Gas immersion depth Format according to item LD . The distance MG specifies the
minimum required distance below a spot before it is taken in the
average gas temperature calculation
TU
= Temperature status conversion One character (default: ‘T’)
This item is used to indicate the temperature status character in
case of a reduced or not guaranteed temperature accuracy. This
is the case when the temperature status is:
•
out of specified temperature range
•
last valid level used
•
manual level used
•
level below lowest temperature element
If required, this item can be set to another character.
EX
Exit Exit protection level 2