All-digital satellite signal simulated source

A pocket size laser power meter adapted to measure the power of laser energy emitted by a laser. The power meter includes a thermal mass adapted to receive the laser energy. A temperature sensor coupled to the thermal mass translates temperature changes in the thermal mass into an electrical sensor signal having a variable voltage. A differentiator coupled to the temperature sensor receives the electrical sensor signal and produces a differentiated signal indicative of the rate of change of voltage of the electrical sensor signal. A cooling rate holding circuit coupled to the differentiator receives a cooling portion of the differentiated signal indicating a lowering of the temperature of the thermal mass. A heating rate holding circuit coupled to the differentiator receives a heating portion of the differentiated signal indicating a raising of the temperature of the thermal mass. A display meter coupled to the holding circuits adds the cooling and heating portions of the differentiated signal together, translates the differentiated signal into a power reading, and displays the power reading to a operator.

Pocket size laser power meter

A laser power meter and associated method are disclosed. The laser power meter has an absorber that is placed in a path of a laser beam during a power measurement, a temperature sensor for measuring the temperature of the absorber, a differentiator for determining a rate of change of the temperature of the absorber, and a processor that computes an estimated power of the laser beam based on the temperature and its rate of change without considering power related loss effects and then computes the power of the laser beam based on the estimated power and the temperature and its rate of change.

Laser power meter

Disclosed is a method for testing the performance of a heat pipe and an apparatus for conducting the performance test. The apparatus includes a heating device and a cooling device. Two ends of the heat pipe are thermally connected to the heating device and the cooling device, respectively. The heating device is applied to supply thermal energy to the heat pipe. When the quantity of thermal energy being transferred to the heat pipe reaches to a specified value, the temperatures at the two ends of the heat pipe are detected. If the temperature difference between the two ends is lower than a predetermined value, the heat pipe being tested is deemed as acceptable.

Method and apparatus for conducting performance test to heat pipe

The invention relates to a programmable digital pulse generator which belongs to the technical field of electron. The traditional generator has strict requirement on a signal, and an output digital pulse signal has poorer performances in aspects of working noise, interference resistance, and the like and can not be directly applied. The programmable digital pulse generator provided by the invention comprises an SRAM (Static Random Access Memory) data storing device, a DDS (Digital Display Scope) frequency generating device, a USB (Universal Serial Bus) communication converting device and a superior PC (Personal Computer) and also comprises an FPGA (Field Programmable Gate Array) waveform generating device and a multipath clock pulse drive control device, wherein a pulse editing system is embedded into the superior PC and connected with the USB communication converting device by the PC; the USB communication converting device is connected with the FPGA waveform generating device; and the FPGA waveform generating device is connected with the multipath clock pulse drive control device, the SRAM data storing device and the DDS frequency generating device. The structure of the invention can output a 16-bit pulse signal which is used as an accurate signal source for being applied to the design and test of electronic products, such as a semiconductor detecting device with a reading circuit, and the like.

Programmable digital pulse generator

A radiation beam calorimetric power measurement system for measuring the average power of a beam such as a laser beam, including a calorimeter configured to operate over a wide range of coolant flow rates and being cooled by continuously flowing coolant for absorbing light from a laser beam to convert the laser beam energy into heat. The system further includes a flow meter for measuring the coolant flow in the calorimeter and a pair of thermistors for measuring the temperature difference between the coolant inputs and outputs to the calorimeter. The system also includes a microprocessor for processing the measured coolant flow rate and the measured temperature difference to determine the average power of the laser beam.

Radiation beam calorimetric power measurement system

A tailpulse signal generating/simulating apparatus, system, and method designed to produce electronic pulses which simulate tailpulses produced by a gamma radiation detector, including the pileup effect caused by the characteristic exponential decay of the detector pulses, and the random Poisson distribution pulse timing for radioactive materials. A digital signal process (DSP) is programmed and configured to produce digital values corresponding to pseudo-randomly selected pulse amplitudes and pseudo-randomly selected Poisson timing intervals of the tailpulses. Pulse amplitude values are exponentially decayed while outputting the digital value to a digital to analog converter (DAC). And pulse amplitudes of new pulses are added to decaying pulses to simulate the pileup effect for enhanced realism in the simulation.

Tailpulse signal generator

The goal of the test bed project is to test portable, unattended chemical analysis instruments that will help verify the compliance of various international agreements on weapons of mass destruction. We report on the design of the test bed and present response curves for the first sensor deployed at the test bed. The architecture of the data- acquisition and display interface utilizes industry standards (LonWorks and CORBA), state-of-the-art developmental tools, advanced data visualization and display tools, and commercial government off-the-shelf software and hardware in order to have a flexible/modular infrastructure for integrating and testing both sensors and software applications for unattended remote monitoring systems. The HAZMAT Spill Center located at the Nevada Test Site will be described as well as the opportunities it offers for testing unattended chemical sensors.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

John Baker

Papers

Radiation beam calorimetric power measurement system

Tailpulse signal generator

DOE cooperative monitoring testbed for unattended chemical sensors