Panametrics DigitalFlow GS868, Programming Manual, Page: 24 / 146

Chapter 1. Programming Site Data
14 DigitalFlow™ GS868 Programming Manual (2-Channel)
Note:
The factory has calculated both the transducer signal path length
(P)
and the transducer signal axial length
(L)
, based on the exact transducer configuration used for the application. These values are engraved on the
flowcell and/or are included in the documentation supplied with the meter.
1.7.3.6 Fluid Type
7. Press [F1] = steam or [F2] = any other gas to select the Fluid Type.
a.
If
OTHER
was selected, enter the speed of sound (in feet per second) in the gas to be measured. Press
[ENT]
. (The
meter will only accept values from 125 to 9000 ft/sec.)
1.7.3.7 Reynolds Correction
8. The
Reynolds Correction factor is a number based on the kinematic viscosity and flow rate of the gas. At the
prompt, press [F1] to turn Reynolds Correction off, or [F2] to turn it on.
• If you select Reynolds Correction, the GS868 asks for the Kinematic Viscosity of the gas (available in the
brochure Sound Speeds and Pipe Size Data, 914-004). Use the numeric keys to enter the correct value and
press [ENT] .
1.7.3.8 Calibration Factor
9. Enter a value for the flow Calibration Factor and press [ENT] . The default value is 1.00. (The meter will only accept
values from 0.5000 to 2.0000.)
Procedure Options
After completing the above steps, the meter returns to the Channel PROGRAM prompt. Continue as follows:
• To continue programming the meter, refer to the menu maps in Appendix A of the
Programming Manual and
navigate to the desired menu. Then, proceed to the appropriate section of the manual for instructions.
• To leave the User Program and retain the previous settings, press [EXIT] twice and then press [F1] = NO at the
SAVE prompt. Any programming changes will be discarded and you will be returned to the data display.
• To leave the
User Program and return to measurement mode, press
[EXIT] twice and then press [F2] = YES at
the
SAVE prompt. Your programming changes will be entered into the meter’s memory, and you will be
returned to the data display.
1.7.4 Setting Up Inputs/Outputs
The following specific tasks may be performed via the I/O submenu:
• Enter a
zero cutoff value to eliminate low flow reading fluctuations
• Set up fixed or live temperature and pressure inputs
•
Set up fixed or live steam quality input for mass flow calculations
While following the programming instructions, refer to the menu map in Figure 12 on page 84 in Appendix A, Menu
Maps. Remember to record all programmed data in Appendix B, Data Records.
1. To enter the I/O submenu, press [F4] at the Channel PROGRAM prompt.
1.7.4.1 Entering the Zero Cutoff
Near zero flow, the Model GS868’s readings may fluctuate due to small offsets caused by thermal drift or similar
factors. To force a zero reading when there is minimal flow, enter a zero cutoff value as described below:
2. Enter the desired Zero Cutoff value and press the [ENT] key. A value of 0.1 ft/s (0.03 m/s) is recommended, but
values from 0–1 ft/s (0–0.3 m/s) are acceptable. The menu returns to the main I/O prompt.
1.7.4.2 Entering the Steam Input
3. At the Assume Saturation prompt, press [F1] = NO to use temperature and pressure to determine the state of the
steam, or press [F2] for the GS868 to assume the steam is saturated.
4. At the
Steam Input Type prompt, press
[F1] to select a temperature input, or [F2] to select a pressure input.
• If you select TEMP , go to step 5.
• If you select PRESR , go to step 7 on the next page.