Dynamax HPFM3, Инструкция по установке и эксплуатации, Страница: 83 / 86

Revision: JUNE 2017 83
APPENDIX IV – Glossary
A/D
The output of the pressure transducers is logged using a custom-designed, dual channel A/D
circuit with 12 bits plus sign accuracy. The location of A/D circuit in the supply box. The HPFM
is supplied with Windows software for controlling the A/D circuits, logging data, and for
preliminary data analysis.
Air Valve, AV
Capillary Tubes, CT
The capillary tubes are 1.5 mm OD HPLC tubing 0.16 to 1.5 m in length.
Captive Air Tank, CAT
The Captive Air Tank (CAT) is a two-compartment tank. The upper compartment contains
water and the lower section can be pressurized with air. A flexible rubber diaphragm separates
the two compartments. The large stainless steel CAT allows you to pressurize the water without
the air and water mixing together. The CAT will hold 7.0 liters of water and it is best to refill
while there is still at least 0.5 liters of water in the tank. The Captive Air Tank (CAT) should be
filled only with ‘degassed water’, i.e., water with air dissolved at less than saturating
concentrations of O2 and N2 at atmospheric pressure. It is important to prevent air bubbles from
entering the Captive Air Tank (CAT) because these bubbles will re-saturate the degassed water.
Cubic Feet, Cu. Ft.
The compressed air tank for the HPFM has a volume of 24 cubic feet.
Differential pressure, dP
Water flow across the selected CT causes a differential pressure (dP) drop (dP = P1 -P2)
measured with PT1 and PT2, respectively. If the software recognizes that the differential
pressure between PT1 and PT2 is over 18 milli-volts or 18 PSI (124 kPa), then it will give you a
message telling you that the HPFM is out of range. The working range for the differential
pressure is 0 to 18 milli-volts. The desired range is 8 to 15 milli-volts. When you are working
with root systems, the differential pressure will normally increase the longer you have the HPFM
coupled to the root.
DT
DW
Water Filter, F
Flow to compress air bubbles, Fb
Elastic flow, Flow associated with elastic swelling, Fe
In order to reduce elastic flow, Fe, always use small-diameter, rigid outlet tubing when using the
two lowest flow rate ranges (Green and Orange).
Rate of passage through the roots, Fh
If the flow through the object measured is a linear function of applied pressure difference
between the outlet of the HPFM and atmospheric pressure.
GQ
Green quick fit connector for adding air to CAT.