Patent ID: 7601964

Claim:
A method for measuring UV pulse total energy, comprising the steps of: detecting a UV pulse having a pulse duration and a pulse total energy at a photo-detector to generate a light detection pulse signal L(t), having a approximately said pulse duration; integrating the light detection pulse signal L(t) with a lossy integrator to generate a running integration signal M(t) that increases over time for approximately said pulse duration to maximum value, and then decays with respect to time, with a given decay rate over a given interval, wherein the maximum is based on the UV pulse total energy, wherein said lossy integrator is composed of an operational amplifier having positive and negative inputs and an output, a feedback leakdown resistor R 1 connected between said output and said negative input and a capacitor C connected between said output and said negative input, said photo-detector being connected across said positive and negative inputs; sampling said running integration signal M(t) from the lossy integrator with an analog-to-digital converter to generate a corresponding digital measurement sample, wherein the M(t)/L(t) transfer characteristic of the lossy integrator is M ⁡ ( t ) ≈ ⅇ - t / R 1 ⁢ C ⁢ 1 C ⁢ ∫ L ⁡ ( t ) ⁢ ⅆ t where M(t) is a running integral of L(t) that leaks towards zero with an exponential time constant of R 1 C, the time constant R 1 C being selected based on a sampling rate of the analog-to-digital converter, the pulse duration of a UV light pulse to be detected and a maximum acceptable error between a maximum value of M(t) and a decayed value of M(t) at a time of sampling by the analog-to-digital converter; processing the digital measurement sample in a digital signal processor circuit, said digital signal processor having an instruction program memory, a processor for executing an instruction program stored in the instruction program memory, a data storage for storing measured UV pulse energy values, an input port connected to an output of the analog-to-digital converter for receiving the digital measurement samples, and an input/output port for outputting data from said data storage and inputting instructions to said instruction program memory; displaying measured UV pulse data on a display connected to the input/output port of the digital signal processor; and receiving user instructions via a user interface connected to the input/output port of the digital signal processor, the user instructions being stored in the instruction memory of the digital signal processor.