Miniature Electronic Pressure Scanners

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ESP-16HD/32HD/64HD

FEATURES
• Unparalleled Long Term Stability
• Individual Offset and Thermal Zero Compensation
• Automatically Switched Reference Pressures
• Optional Isolated Purge Capability
• Optional Temperature Sense Output
• Optional Digital Temperature Compensation (DTC)

APPLICATIONS
• In-Model Windtunnel Testing
• Aircraft Flight Testing
• Automotive Track Testing Fully integrated 5 digit display and power supply for a wide choice of gas mass flowmeters, capacitance manometers and all-media pressure transducers


Miniature ESP electronic pressure scanners are differential pressure measurement units consisting of an array of silicon piezoresistive pressure sensors, one for each pressure port. The sensors are mounted on a common hybrid glass substrate using a proprietary technique which maximizes long term stability. The outputs of the sensors can be electronically multiplexed through a single onboard instrumentation amplifier at rates up to 20,000 Hz using binary addressing. The multiplexed amplified analogue output is capable of being driven through long lengths of cable to a remote A/D converter. The ESP scanners also incorporate a two position manifold actuated by momentary pulses of control pressures. When placed in the calibrate position, all sensors are connected to a common calibration pressure port. A series of accurately measured pressures can be applied through this port to characterize the sensors, in place, at the condition to which they are being subjected. Proper and periodic on-line calibration maintains static errors within +/-0.05% of the full scale (FS) pressure range. The calibration manifold automatically switches between two common reference pressures to ensure a stable reference is applied during calibration.		The calibration manifold incorporates a visual position indicator and utilizes a dynamic o-ring seal design for high reliability and easy servicing in the field. Options include purge capability, isolated from the pressure sensors, to clear measurement lines of moisture and contamination as well as to prevent closure of model pressure taps during application of pressure sensitive paint. Other options include a nickel foil RTD output to monitor internal scanner temperature and Digital Temperature Compensation (DTC) technology for use with the SDI configuration of PSI's System 8400 which reduces calibration requirements by up to 90%. The DTC option incorporates the latest PSI innovations in ESP technology including temperature signal outputs from each silicon pressure sensor, embedded EEPROM retaining factory calibration information including temperature characteristics, programmable dual gain amplifier, calibration manifold position sensing and internal sensor excitation regulation with sense output. The ESP scanners can be used with CANdaq, ScanDaq and the PSI 8400 system.
For full specification please download the PDF data sheet (632kb).
DTC Technology
Digital Temperature Compensation (DTC) The DTC option of the ESP pressure scanners incorporates many advanced features to increase the utility of the scanners while providing digital temperature compensation of the silicon sensors. An onboard EEPROM stores the thermal calibration data for each channel. Also stored in the EEPROM is information identifying the range of the scanner, the number of channels, the model number, the serial number, the date of manufacturer, the date of calibration, and the model and serial number of the calibration unit used to calibrate the scanner. This data is serially transmitted to the Scanner Digitiser Interface (SDI) of the System 8400 using the ESP address lines and then transferred to the 8400 System Processor via fiber optic cable. Using a proprietary PSI-developed method, the temperature of each sensor within the scanner is measured and transmitted along with the raw pressure measurements to the 8400 System.		Utilizing the calibration data within the EEPROM, the System 8400 compensates for temperature changes to the sensors in real time. This reduces thermal errors by a factor of 20 thereby reducing on-line calibration requirements by up to 90%. The ESP scanners also incorporate a hall effect sensor which is used to indicate the position of the calibration manifold. This position information can be transferred to the system upon command. Another advanced feature is the ability to derange the ESP scanner upon command. This alters the gain on the amplifier to derange the scanner by a factor of three, enabling additional windtunnel tests to be conducted without reinstrumenting the model with lower range ESP scanners.

For full specification, please download the PDF data sheet (632Kb).