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) • New 4" water (1.0Kpa) range available.
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
Pressure Systems Announces the Gen-2 ESP-32HD;
the initial offering of our Second Generation Version of Miniature
ESP Pressure Scanners
Pressure Systems has developed a next
generation (Gen-2) amplifier circuit that dramatically enhances
the performance of our industry-leading miniature ESP scanners
used in Windtunnel and Flight Test research. Through innovative
circuit design and material selection, we have improved the sampling
speed of the ESP scanners in excess of twice that of the original
generation while further reducing noise and increasing EMC immunity.
The new amplifier assembly maintains the primary physical attributes
of the original design and can be retrofitted onto existing scanners.
The first scanner model available with Gen-2 capability is the DTC Series of
ESP-32HD scanners. The new amplifier circuit increases the sampling rate of the
scanner from 20,000 to 50,000 samples per second. The new amplifier assembly
facilitates a slightly smaller scanner package by reducing the length by 0.30”.
Scanner mounting hole locations have therefore changed accordingly. For customers
using heater chambers, the smaller length also means a change to the top plate
to facilitate the scanner cable exit.
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.
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 (1,128Kb).
