PACE CM3 Article: Where speed and accuracy combine
10Pages

a Baker Hughes business Where speed and accuracy combine

Druck, a Baker Hughes business, has been developing and delivering pressure measurement solutions to customers for more than 40 Years, across many applications in Aerospace, Oil & Gas, Industrial, Metrological Laboratories and many others. One of Druck’s main areas of technical expertise is Pressure Controllers. These are used in many different industrial applications and by metrological laboratories as calibration standards around the world. Druck’s PACE pressure controllers are widely recognised as the world’s fastest, with the ability to fill and control volumes of 300cc in under 5...

PACE CM3 will utilise Druck’s established TERPS® (Trench Etched Resonant Pressure Sensor) technology at its core, which delivers unprecedented metrological characteristics and resultant levels of performance for PACE controllers. This paper will present the main attributes of PACE CM3 enabled pressure controllers and resultant performance, namely: Druck’s PACE widely recognised as the world’s fastest • TERPS® technology • ccuracy and its factors A • ong Term Stability L • ressure controlling abilities P • ACE’s modular construction using control modules such as PACE CM3 P • utomated...

TERPS® Technology TERPS® relies on the straining of a resonant structure to change the frequency of the transducer, which is proportional with the pressure applied onto the sensor’s diaphragm. The unique design of TERPS® is the base of its great performance, especially in terms of drift and hysteresis (pressure & temperature). The unique design of TERPS® is the base of its great performance RPT Die Isolation Diaphragm Pressure connector Figure 1: Isolated TERPS configuration The TERPS® structure and build has the following characteristics: The TERPS® structure and build has the following...

The entire TERPS structure is mechanically and dynamically balanced External pressure deflects the resonator Figure 2: Isolated TERPS configuration The whole structure (diaphragm and resonator) is mechanically and dynamically balanced to ensure that as pressure (i.e. strain) is applied, the change in frequency occurs in a continuous manner, without signal discontinuities. This is particularly important in providing the high precision of the transducer and whilst Druck quote precision as 15 ppm FS on the product datasheet, many of the Druck’s TERPS outperform this specification. As per the...

Regarding accuracy, other manufacturers’ instrumentation may be defined in alternate methods which have subtle implications for the user. For example: Definitions of accuracy should consider the application and the needs of the customer Manufacturer A expresses accuracy as: 80ppm rdg down to 33%FS then 80ppm of 33%FS Manufacturer B expresses accuracy as: 100ppm rdg or 30ppm %fs whichever is the greater. Figure 3 demonstrates how Druck’s PACE performs when comparing accuracy against other Pressure Controller manufacturers. Further accuracy improvements can be made on a PACE6000 if utilising...

Druck has introduced an innovative method of taring the drift against a highly accurate barometric sensor TERPS Drift ppm FS Typical Piezoresistive Sensor Drift Spec ppm FS Claimed Piezoresistive Sensor Drift Spec ppm FS Figure 4: TERPS® drift performance versus competitor’s specifications Both 2 & 3.5 bar absolute exhibit similar behaviour in terms of drift performance. However, for ranges of 8 bar absolute pressure and above, Druck has introduced an innovative method of taring the drift against a highly accurate barometric sensor, which is included in all Druck’s PACE CM3 control modules....

Control Stability and Offset Importance When a pressure controller is used in an automated calibration system, the time taken to get to the setpoint and stabilise is often critical in achieving increased flow through the production line without sacrificing accuracy. Druck’s PACE pressure controller is the market leader in time taken from command to setpoint, because of the advanced pressure control algorithm. Once the controller has stabilised controller noise and offset will also impact the speed of measurement taken. When the controller is ‘noisy’, readings must be averaged over a period...

PACE’s modular construction The modular nature of PACE’s construction means that existing customers can easily upgrade their PACE controllers from CM2 (or below) to the improved accuracy CM3 range with very little downtime being incurred. There is also the added benefit that the control module itself can be shipped to Druck for upgrade, repair or calibration by itself, without having to remove the chassis from any rack or testbench, thus providing further savings on downtime and maintenance costs. This also allows for the Druck Service team to perform a health check on the entire control...

Automated Calibration and Data Integration using Druck’s 4Sight2 Calibration Management Software 4Sight2 Calibration Management Software offers end-to-end automated calibration with PACE CM3 Druck’s 4Sight2 Calibration Management Software integrates seamlessly with its PACE pressure controller to offer end-to-end automated calibration. There are no manual interventions and therefore this eliminates documentation errors and increases the quality of calibration data. 4Sight2 controls Druck’s PACE and DPI range of digital pressure indicators and calibrators, running tests which can be...