Panametrics Sentinel LCT, User Manual

Page: 72 / 248

Chapter 4. Advanced Programming
60 Sentinel LNG User’s Manual
4.3 Entering Signal Parameters (cont.)
6. The next prompt requests the
Zero Cutoff
. Near “zero” flow, the
Sentinel LNG
may have fluctuating readings due to
small offsets (caused by factors such as thermal drift in the fluid). The zero cutoff causes velocity measurements
less than the cutoff to be reported as zero. To set the cutoff, press [ENT] , and use the arrow keys to enter the new
value. Press [ENT] to confirm the entry.
7. The next prompt requests the
Peak Detection
method. In the “
Peak
” method, the peak is identified by testing a
derivative of the signal. In the “
Threshold
” method, the peak is identified as the point where the signal crosses a
threshold that is a percentage of the maximum signal detected. The peak method is more reliable in identifying
the signal in dynamic conditions, while the threshold method is more reliable in marginal signal conditions.
Note: Do not change the peak detection method or values unless recommended by the factory.
a.
Press
[ENT]
. The screen shows the two display options,
Peak
and
Threshold
. Scroll to the desired option, and press
[ENT] .
b. The next screen depends on your selection in Step
a
.
• Select
Peak
, and no further options are available. Press [ESC] to return to the Signal menu.
• Select
Threshold
and press [ENT] , the screen shows three parameters:
Min Threshold, Max Threshold
and
Percent of
Peak
. For each parameter, press [ENT]. Use the arrow keys to enter the new value, and press [ENT].
8. The next prompt requests
Velocity Averaging
, in which users select a velocity measurement to smooth out noise in
the signal. Press [ENT] , and use the arrow keys to change to the desired number. Press [ENT] to confirm the entry.
9. The next parameter is the
Sample Size
, the number of pulses each transducer (upstream and downstream) emits.
It is set to
8
by default. Press [ENT], and use the [

] and [

] keys to scroll to the new number (from
1
to
32
). Press
[ENT] to confirm the entry.
10. The next prompt requests
Batch Size
. Press
[ENT]
and use the [

] and [

] keys to scroll to the new number (from
1
to
32
). Press [ENT] to confirm the entry.
11. The next parameter is the
Max Samples/Cycle
. Press
[ENT]
and use the [

] and [

] keys to scroll to the new number
(
32
,
16
or
8
). Press [ENT] to confirm the entry.
12. The next parameter is the
Tx Bark Code
. Press
[ENT]
and use the [

] and [

] keys to scroll to the new option (
AUTO
,
OneBit
,
TwoBit
,
Fourbit
,
ElevenBit
, or
Pulse1Bit
to
Pulse16Bit
). Press [ENT] to confirm the entry.
13. The next prompt is
RxW Size
. Press
[ENT]
and use the [

] and [

] keys to scroll to the new option (
8192
,
4096
,
2048
,
1024
,
512
, or
256
). Press [ENT] to confirm the entry.
14. The next prompt is
Gain Mode
. Press
[ENT]
and use the [

] and [

] keys to scroll to
AUTO
or
Manual
. If you select
AUTO
and press [ENT] the screen returns to the
Signal
menu. If you select
Manual
,
DAC Counts
appears. Press [ENT], use
the arrow keys to enter the new value, and press [ENT].
15. The next prompt is
Delay Time
. To change the delay time, press [ENT], use the arrow keys to enter the new value,
and press [ENT].
16. The next prompt is
ActiveTw Tbc
. To change the numeric value, press [ENT], use the arrow keys to enter the new
value, and press [ENT].
Entering parameters in the
Signal
option has been completed. Press [ESC] to return to the PROG menu, or continue
pressing [ESC] until the display screen reappears.
4.4 Entering the Meter Correction (K) Factor
With the
K Factor
submenu, calibrate or adjust the
Sentinel LNG
readings to another flow reference. While following the
programming instructions, refer to Figure 231 on page 212. To enter
K Factor
data:
Note: From the PROG menu, proceed directly to Step 4. To select a different option, scroll to that option and press
[ENT] twice to select it (once to enter and again to confirm the selection).
1. Press [ESC] . The
Sentinel LNG
enters the
User Program
.
2. Press the [

] key until PROG is bracketed in the top left corner and press [ENT] .
3. Use the [

] and [

] keys to scroll to the desired
Channel
and press [ENT] .
4. Scroll to the
K Factor
submenu and press [ENT] .
5. The screen shows three options:
Off, Single
and
Table
. Scroll to the desired option, and press [ENT].
6. The menu varies, depending on the selection in Step 5.