1 GPa Gas Pressure Regulators
The 1 GPa Gas Pressure Regulators supply continuously-loaded high-pressure cells with helium up to 1 GPa (10 kbar). Each system, built by SITEC, consists of a pneumatic-driven 2-head diaphragm compressor for pre-filling the system and the sample with helium up to 200 MPa, and a primary pump driving the pressure intensifier up to 1 GPa. The control loops and the different modes of control operation are performed on a Eurotherm Mini8 PLC. The graphical user interface is programmed with LabView on a panel PC with touch screen.
The pressure generation system is designed for controlled pressurisation and depressurisation. The pressure intensifier piston position is measured and indicated. If the piston has reached the upper end position, the automatic re-filling procedure is activated. In standard operation, NOMAD communicates via an Ethernet interface (Modbus TCP/IP) with the PLC. A list of the relevant PLC registers is provided below.
The compressors, pressure intensifier, valves, controller and related electronics are packed in a crate that is brought to the instruments. It also features two rollers of cables (230V and compressed air). The Florinert level in the tank is measured and indicated. On the GUI, the mode of operation can be changed to manual mode. In this mode, a simple pressure ramp up or down can be started. This makes it possible to test a pressure profile step by step.
PLC Registers (Eurotherm Mini8 Loop Controller)
Description | Read | Write | Address |
---|---|---|---|
Actual value PT1 (intensifier outlet) | X | 4228 | |
Actual value PT2 (sample) | X | 4229 | |
Actual value PT3 (intensifier inlet) | X | 4230 | |
Actual pressure compressed air | X | 4231 | |
Piston position (intensifier) | X | 4232 | |
Filling level B1 (FC-770 Fluorinert level) | X | 4233 | |
Actual value PT4 | X | 4234 | |
Emergency switch | X | 4251 | |
Output signal control valve compressed air | X | 4252 | |
Output signal control valve (intensifier pressure relief) | X | 4253 | |
Output signal control valve (sample pressure relief) | X | 4254 | |
Actual control phase | X | 4962 | |
Target set point (remote control) | X | X | 4963 |
Intensifier ratio limit | X | 4964 | |
Maximum pressure | X | 4965 | |
Working set point | X | 4966 | |
Target set point (LabView) | X | 4968 | |
Remote control active | X | 4969 | |
Set point ramp rate | X | X | 4970 |
Firmware version (Mini8) | X | 4971 | |
Offset PT1 (intensifier outlet) | X | 4972 | |
Offset PT2 (sample) | X | 4973 | |
Offset PT3 (intensifier inlet) | X | 4974 | |
Perform intensifier check | X | 4975 | |
Pressure increase disabled | X | 4976 | |
Ramp reached | X | 4977 | |
Timeout leak detection compressor (minutes) | X | X | 4978 |
Leak detection enabled after programming start (hours) | X | X | 4979 |
Reset "pressure increase disabled" | X | X | 4980 |
Pressure alarm | X | 5071 |