Meriam M2110L SMART LEVEL GAUGE - Manual (Page 14)

9R143 Dated 3/2011
12
P3 – RESIDUAL HYDROSTATIC PRESSURE
The M2110L Smart Level Gauge will correctly measure level when used with a dip tube or as a direct-head pressure
reading of the tank’s fluid column. Register P3 is used to describe the unmeasurable pressure below the dip tube, or
the additional pressure created by a “dead leg” in the direct-head piping. This register must be specified in Inches of
Water Column at 20
o C reference.
QUICK REFERENCE: P3, RESIDUAL HYDROSTATIC PRESSURE
Px Name Description Value Range Notes
P3 Residual
Hydrostatic
Pressure
Identifies the Pressure lost or
added due to piping
configurations.
-9999 to +9999
inH
2
O @ 20ºC.
+Val:Dip Tube
-Val: Dir.Head
Dip Tube Application Direct
Head Measurement
The P3 register specifies the pressure created by the
height of the fluid below the dip tube to the bottom of the
tank. The volume in the tank below this point cannot
be measured! To compensate for this unmeasured
volume (optional), enter this register as a positive value. The P3 register specifies the pressure caused by the
vertical “dead leg” of the piping to the gauge. This is
additional pressure applied to the gauge that is not
due to fluid volume in the tank. To compensate for
this pressure, enter this register as a negative value.
Note: The Low Pressure side is connected to the tank top on pressurized tanks only, as shown, using a differential
pressure, non-isolated model (DN) Smart Level Gauge. It is recommended that a gauge-pressure, isolated sensor
model (GI) Smart Level Gauge be used whenever possible for measuring fluid level (vented tank).
The differential pressure, non-isolated sensor (required for pressurized tanks) is compatible with clean, dry, non-
corrosive gases only. This will work without modification in most bubbler system applications. However, when
corrosive liquids or vapors are in the tank, a diaphragm seal will be needed on the high and low pressure lines (or
on the high pressure line in a direct head pressure system). Consult the factory for information on diaphragm seal
selection, limitations, and the effects on overall gauge performance.
STEP BY STEP: P3, RESIDUAL HYDROSTATIC PRESSURE
Step Action Display
1 Gauge should be in the normal Measure Mode. Normal Pressure Display.
Press the PRGM/Enter
→ key.
2
If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 21.
The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.
All Models