Setting The Ambient Temperature (The 3102/3105) - Emerson Rosemount 3100 Series Reference Manual

Reference Manual
00809-0100-4840, Rev. BA
July 2008
Setting the Ambient
Temperature
(The 3102/3105)
To clear all the stored false echoes:
a) After entering the "Eng" menu (see the note above), press the green
↓
button repeatedly until "Lrn" is indicated.
b) Press the blue button
c) With the display indicating "LrnX", press and hold the green button
ten seconds to clear the memory. The display then indicates "Lrn0".
d) To exit to the menu system press the red button
re-appears; see the previous procedure for how to store new false echoes
or press the green button
Screen display:
Factory default value:
The transmitter has an integral temperature sensor to measure the
temperature of the air space surrounding it so that the speed of sound can be
correctly computed for sending pulses. The distance-to-target is then
calculated using the formula:
Distance to target = Speed of Sound in air * (Time for echo to return / 2)
Auto indicates the transmitter is set to continuously measure the temperature
using the integral temperature sensor. It may, occasionally, be necessary to
over-ride this automatic monitoring and fix the temperature to be used in
speed-of-sound calculations, for example if the air temperature is not uniform
and the temperature being recorded is not the true air temperature.
NOTE:
This menu option is in the engineering menu "Eng". See "Accessing the
Engineering Menu (The 3102/3105)" on page 5-6 or see Figure C-4 on
page C-5 for a map of the menu structure.
To edit and fix the temperature:
a) After entering the "Eng" menu (see the note above), press the green
↓
button repeatedly until "t" is indicated.
b) Press the blue button
indicates the present setting.
c) If this setting is correct, press the red button
(The menu option "t" re-appears".)
d) Press the blue button
"Auto", press the green button
first of the three digits flashes to indicate a number can now be edited.
e) Press the green button
(To restore the "Auto" setting, scroll past "9" and press the red button
save and exit.)
f) Press the blue button
indicate it can be edited.
g) Repeat steps (e) and (f) until the last digit is flashing, and edited as
required.
h) Press the blue button
Rosemount 3100 Series
→
to enter the "Lrn" menu.
↓
to get to the next menu option.
t
Auto
→
to enter the temperature menu. The display
↵
→
to start the editing mode. If the present setting is
↓
to change to a three digit number. The
↓
repeatedly to edit the flashing digit.
→
to move to the next digit. The digit flashes to
→
to confirm the new value. (The flashing stops.)
↓
for
↵
. The menu option "Lrn"
to exit to the menu.
↵
5-13
to