4220 Flow Meter Section 2 Programming
2.4.4Step 2 - Flow Conversion (Level-to-Flow Rate
This value is provided because conductivity rises (~2%/ °C) with temperature. The default setting is 1.91%. This value is the tem- perature coefficient for pure KCl (potassium chloride) in water. For other salts this value will be somewhat inaccurate, but it does provide a close approximation for solutions of many common salts, such as NaCl (sodium chloride), NH4Cl (ammonium chloride) and sea water. If you use the value of 1.91, in most cases you will be able to identify that gross changes are occurring in the ionic content of the stream. If you move with the right arrow, the following options will appear on the display:
YSI 600 CONDUCTIVITY PARAMETER
• YSI T.D.S. • • NOT MEASURED •
T.D.S. stands for “total dissolved solids.” T.D.S. are measured in parts per thousand (ppt).
TDS SCALE FACTOR 0.75
Total dissolved solids are estimated by multiplying conductivity by an empirical factor. This factor can vary between 0.55 and 0.9 depending on the solubility of the ions in the water and its tem- perature.
YSI 600 TEMPERATURE UNITS
• °F • •°C • • NOT MEASURED •
Select the appropriate temperature units.
)
FLOW CONVERSION TYPE
• WEIR/FLUME • • EQUATION • • MANNING • • DATA POINTS •
WEIR/FLUME = weir or flume; EQUATION = equation; MANNING = Manning; DATA POINTS = data points.
If you select WEIR/FLUME, the following will appear:
TYPE OF DEVICE:
• WEIR • • FLUME •
For detailed information on weirs and flumes, refer to the Isco Flow Measurement Handbook. Consulting the manufacturer of the specific weir or flume is also worthwhile. Note that for weirs and flumes, there is a preferred location for installing the level measuring device. Proper mounting of the level measurement device and accurate measurement of the level in the flow stream at the calibration point are essential for accurate flow calculation by the flow meter. If you select WEIR, the following display will appear:
SELECT TYPE OF WEIR:
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