RPM4 is much more than a traditional pressure indicator
State of the art performance from very low pressure to 280 MPa (40 000 psi)… advanced on-board features…compact and rugged…full local and remote communications…RPM4 is the perfect solution in a wide variety of high end pressure calibration, testing and measurement applications.
SDS™ Q-RPT Self Defense System™
All Q-RPT modules up to 7 MPa (1 000 psi) include the Fluke Calibration unique Self Defense System (SDS). SDS valves automatically isolate and vent the module’s Q-RPT when it is not in use or an overpressure is about to occur. With SDS, any Q-RPT module can be left connected to pressure up to 10 MPa (1 500 psi) without needing to isolate or disconnect it.
Infinite Ranging™ and AutoRange™
Infinite Ranging gives RPM4 unprecedented versatility in adapting to the specific range of operation. With the easy to use AutoRange function, a few simple key strokes or a single remote command string at the start of a test adapt every feature of the pressure monitor to optimize it for the range to be covered. Just enter the maximum pressure and the measurement mode.
AutoRange then:
• Selects and activates the most appropriate Q-RPT to cover the specified range and measurement mode.
• Sets the pressure unit of measure.
• Activates absolute, gauge or compound gauge measurement.
• Adjusts display resolution to the appropriate level for the range.
• Adjusts overpressure alarms to the actual range of operation.
• Reduces measurement uncertainty proportionally to the selected range (premium class Q-RPTs only).
Quartz reference pressure transducer (Q-RPT) modules
RPM4’s outstanding pressure measurement specifications are made possible by DHI's 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 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. Standard and premium class Q-RPT modules are available to best fit your performance and budgetary requirements.
A unique dynamic compensation for atmospheric pressure system uses an independent on-board barometer to provide seamless switching between absolute, gauge and compound gauge modes at any time. 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.
Q-RPT modules offer the advantages of:
• % of reading measurement uncertainty with AutoRange span turndown available
• Negligible warm up time
• No gas species dependence
• Quartz element isolated from test medium 
• Low sensitivity to orientation
Reference Pressure Barometer RPM4 BA100K
The RPM4 BA100K is a full function laboratory quality barometer intended to measure atmospheric pressure with the very highest performance. Its outstanding pressure measurement specifications are made possible by DHI's exclusive quartz reference pressure transducer (Q-RPT) modules.