High-speed Data Acquisition Unit Research Articles

Field Intensity Detection of Individual Terahertz Pulses at 80 MHz Repetition Rate

We present a new approach to detect the intensity of individual terahertz pulses at repetition rates as high as 80 MHz. Our setup comprises a femtosecond fiber laser, an InGaAs-based terahertz emitter, a zero-bias Schottky detector, and a high-speed data acquisition unit. The detected pulses consist of two lobes with half-widths of 1–2 ns, which is much shorter than the inverse repetition rate of the laser. The system lends itself for high-speed terahertz transmission measurements, e.g., to study wetting dynamics in real time.

Torque Performance Measurement System for Spring in Seat Belt

To acquire torque performance in seat belt conveniently and precisely, the measurement scheme based on stepper motor was established. The hardware was developed with high-speed data acquisition unit based on PCI protocol. The software which includes user interface and data acquisition control module etc was developed with multithread technique and document-view architecture. The experiments with seat belt spring show that the max torque error of the system is 0.08N.cm. The system has merits of high precision, easy operation and can provide reliable data for spring torque performance in seat belt.

Measurement of Rotating Blade Tip Clearance with Fibre-Optic Probe

This paper described a tip clearance measuring system with fibre-optic probe. The system is based on a novel tip clearance sensor of optical fibre-bundle mounted on the casing, rotating speed synchronization sensor mounted on the rotating shaft, the tip clearance preamplification processing circuit followed by high speed data-acquisition unit. A novel tip clearance sensor of trifurcated optical fibre bundle was proposed and demonstrated. It is independent of material of measured surface but capacitive probe demands target conductive. Measurements can be taken under severe conditions such as ionization. Sensor circuitry and data acquisition circuit were successfully designed. With the help of Rotation synchronized sensor, all the blades can be detected in real-time. Because of fibre-optic sensor, the measuring system has commendably frequency response, which can work well in high rotating speed from 0-15000rpm.The measurement range of tip clearance is 0-3mm with 25um precision.

Tunable diode laser spectroscopy using the IBM PC

This paper describes a dual-beam, tunable diode laser (TDL) spectrometer built for gas-phase vibrational spectroscopy studies. It employs a commercially available cryogenic cooler and control electronics and can incorporate Pb-salt diode lasers with operating wavelengths from 7 to 12 μm. The instrument optics have been largely assembled using inexpensive reflecting components. An IBM personal computer with enhanced graphics and high-speed data-acquisition unit permits dual-channel sweep averaging (normally done with expensive, commercial hard-wired units) as well as on-line spectral line parameter calculations. Such an arrangement puts this type of laser spectroscopy capability within reach of undergraduate physics and chemistry programs.