Abstract: A vehicular ignition interlock system having a flow rate integrator and a servograph. The integrator is provided to insure that only "deep lung air" is analyzed for alcohol. A pressure transducer is employed in the integrator such that the output of the transducer is proportional to the air flow rate. As the rate of flow of a breath sample varies, a corresponding change in the required duration of the breath sample is made to insure that a deep lung air sample is being analyzed. The servograph comprises a plurality of colored lights and a tone generator which are controlled by a computer to direct the operator to adjust the rate of flow of his or her breath sample in accordance with the visual indication provided by the lights. Thus the servograph and the flow rate integrator insure that only a human subject will be capable of providing the air sample to be analyzed. A gas sensor and flow sensor are mounted in a replaceable module to facilitate field repair, replacement and calibration.

Abstract: A reference system utilizes pulsed arc light excitation which excitation pulses are directed onto a flow cell containing a fluorescent dye. Fluorescent light emitted from the dye is guided to a photomultiplier tube which converts it to electrical pulses. A portion of each excitation light pulse is guided by a light pipe onto a PIN diode light detector which converts these light signals to electrical pulses. A LED reference light source is pulsed to generate a plurality of reference light pulses one of which occurs between each excitation pulse. A portion of each of these pulses is guided to each of the two light detectors and two more series of electrical pulses are generated. A microprocessor then reads the four electrical pulses resulting from each pair of light pulses and performs a computation on the resulting numbers which indicates the relative concentration of the target concentration being assayed.

Abstract: There is disclosed herein a reference system for a fluorometer designed to detect very low levels of materials tagged with fluorophores. There is also disclosed an optical system for use in such a system which improves the signal to noise ratio. The reference system utilizes pulsed arc light excitation which excitation pulses are directed onto a flow cell containing the fluorescent dye. Fluorescent light emitted from the dye is guided to a photomultiplier tube which converts it to electrical pulses. A portion of each excitation light pulse is guided by a light pipe onto a PIN diode light detector which converts these light signals to electrical pulses. A LED reference light source is pulsed to generate a plurality of reference light pulses one of which occurs between each excitation pulse. A portion of each of these pulses is guided to each of the two light detectors and two more series of electrical pulses are generated.