PPC4 is a stand-alone pressure controller intended for precision setting and control of gas pressure into a closed volume as is commonly needed for the calibration and testing of pressure measuring instruments. It has been designed to provide very high performance combined with maximum versatility and ease of use.
PPC4 can be equipped with a low cost utility sensor for pressure monitoring or one or two Quartz Reference Pressure Transducers (Q-RPTs) to allow it to set and measure pressure with very low measurement uncertainty. Up to two external Q-RPTs in an external Reference Pressure Monitor (RPM4) can also be integrated into a PPC4 system. In some cases, a barometer is included.
Pressure control is achieved by a patented pneumatic module based on digitally controlled solenoid valves and differential pressure regulators.
PPC4 is controlled locally by the operator using a front panel display, keypad and function keys or remotely by a computer using ASCII character command strings over RS232, IEEE-488.2 or Ethernet.
PPC4 models are available to measure and control pressure in ranges from as low as - 3 to 3 kPa to as high as 0 to 14 MPa in absolute, gauge and compound gauge measurement modes. 
Quartz reference pressure transducer (Q-RPT) modules 
PPCH’s outstanding pressure measurement specifications are made possible by the Fluke Calibration exclusive quartz reference pressure transducer (Q-RPT) modules.
Q-RPTs measure pressure by measuring the change in the natural oscillating frequency of a quartz crystal with pressure induced stress. To be qualified for use in a Q-RPT module, each transducer is individually evaluated and characterized using automated primary pressure standards. Only transducers exhibiting required levels of linearity, repeatability and stability are selected. A proprietary compensation model, derived from more than 15 years experience with thousands of quartz pressure transducers, is applied to optimize the metrological characteristics needed in a transfer standard. 
PPCH can be delivered with a low cost utility sensor for applications in which the high precision and stability of a Q-RPT are not required.
Q-RPT modules integrate the quartz transducer into a rigid, standardized assembly that protects the critical measuring elements from undesired connecting stresses. Modules include valves to support AutoZeroing, measurement mode changes and switching of the active Q-RPT.
Dynamic atmospheric pressure compensation, using an independent on-board barometer, allows instantaneous switching between absolute, gauge and bidirectional gauge modes at any time with no significant effect on measurement uncertainty. The barometer is used only to measure the small variations in atmospheric pressure that occur during gauge mode operation, so its absolute error and drift over time do not contribute to measurement uncertainty, and it does not require formal calibration. No additional hardware or options are needed to support both absolute and gauge modes with a single Q-RPT. 
Infinite ranging™ and autoRange™
There’s a lot more to covering a wide range of test devices with a single pressure controller than “% of reading” measurement uncertainty.
In addition to the necessary measurement uncertainty, PPCH offers the full pressure control and feature adaptability that are needed for true rangeability in test and calibration applications.
Infinite Ranging gives PPCH unprecedented versatility in adapting to a wide variety of devices to be tested. With the easy to use AutoRange function, a few simple key strokes or a single remote command string at the start of a test adapts every feature of the controller to optimize it for a specific range.