Bartec HYGROPHIL H 4230-10 A Series, Руководство по эксплуатации

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System description
5
Operating Instructions HYGROPHIL® H 4230-10 Serie A BA 030520
1.3.2 Ejector
The lower section of the measuring chamber contains the ejector, an air jet
pump that pumps the measurement air through the measuring chamber by
means of compressed air. Negative pressure of up to -200 hPa is allowed at
the extraction point. By controlling the compressed air that is fed, the gas
flow rate is kept constant at 14 standard litres per minute. The actuator is a
proportional valve controlled by pulse width modulation. The actual-value
sensor is the venturi system in the upper section of the measuring chamber
in connection with a differential-pressure sensor.
1.3.3 Hose pump
The hose pump propels the water from the storage tank into the measuring
cell. The pump’s delivery rate is regulated in such a way that part of the
water flows out of the cylinder.
1.3.4 Water detector
The water detector uses a capacitive proximity switch to make sure that the
water level in the measuring cell remains correct.
1.3.5 Control and evaluation electronics
The signals for dry temperature, humid temperature, differential pressure
and measuring chamber pressure are passed to the electronics unit, where
a microprocessor is used to calculate the desired humidity measurement
variables and monitor the equipment’s functions.
The following measurement variables are recorded or calculated by the
electronics unit and can be displayed and saved on the PC:
● Dry temperature
TT
● Humid temperature
HT
● Absolute pressure
SP
● Differential pressure

P
● Auxiliary temperatures
T1
external
(via ext. temperature sensor)
T
internal
(for compensating HT)
● Dew-point temperature
DT
● Absolute humidity
MH
● Specific humidity
SH
● Volumetric water vapour content Vol%
● Partial water vapour pressure
VP
● Enthalpy
h
● Saturation deficit
DVP
● Relative humidity for T1
external
RH
The following monitoring and control functions are carried out:
● Open-loop control of the proportional valve for regulating air flow rate
● Closed-loop control of the gas sampling hose temperature
● Monitoring and verification of
• Water level internal, option: external
• Air flow rate
• Temperature sensors
• Adherence to the measurement range at outlets
• Gas sampling hose temperature
• Plausibility of calculation results
Variables calculated
Variables measured