Humboldt HM-4160 FlexPanels - Manual (Page 19)

The pressure should be checked and adjusted after approximately 15 minutes
and then checked periodically when taking readings on from the Burettes.
Toggle Valve
The Toggle Valves are all connected in a series of tees, leading to the Digital
Display on the Control Panel. When the Toggle Valve is lifted, the pressure
for the adjacent Control Burette is indicated on the Digital Display. Only one
Control Burette pressure can be read at one time.
Bias Valve
Burette Section 2 (Base) is the only section with a Bias Valve (BA). This valve
is located below the Section 2 Toggle Valve. The Bias Valve (BA) is used to
combine the output pressure of Section 2 (Base) with that of Section 1 (Cell).
This is accomplished through the use of an extra port in the Regulator for
Section 1, which allows it to connect the output from Section 2 (Base) via the
Bias Valve. When the Bias Valve is open, it will connect the output of Section 2
with Section 1. Therefore, when adjustments are made to the Section 2 (Base)
Regulator (R2) the Section 1(Cell) Regulator (R1) will be changed by the same
amount. This feature can be used during back pressure saturation, allowing the
operator to use the Section 2 regulator (R2) to alter pressures, which maintains
the pressure difference between Section 1 (Cell) and Section 2 (Base).
Bridge Valve
Section 3 (Top) is the only Section with a Bridge Valve. This valve is located
below the Section 3 Toggle Valve. The Bridge Valve, when open, connects the
output of the Section 2 Regulator, to the top of the Section 3 (Top) Control
Burette. The Section 3 Pressure Selection Valve (A3) should be in the off position
when using the Bridge. If the Bias and Bridge Valves are both open, the Section
2 Regulator can be used to increase the pressure equally to all three Control
Burette Sections.
Burette and External Valves
These valves are located at the bottom of the controls in each Control Burette
Section. The Burette Valve is connected to the bottom of the Internal Burette
of the Burette Assembly, while the External Valve is connected to the Outer
Burette. Opening one or both of these valves connects them with the Quick
Connect in Section 1 (Cell). When the Burette Valve is open, the Internal Burette
is connected to the Section 1 Quick Connect. When the External Valve is open
the External Burette is connected to the Section 1 Quick Connect. These Valves
can both be open at the same time, which results in the Internal and the External
Burette seeking the same water level. When monitoring volume changes, only
the Burette Valve should be open.