All wavelength ultraviolet intensity monitor

• US 5,591,978 A
• Filed: 07/27/1994
• Issued: 01/07/1997
• Est. Priority Date: 07/27/1994
• Status: Expired due to Fees

• Current Assignee: BHK
• Original Assignee: Alvin Kovalsky
• Inventors: Kovalsky, Alvin, Miller, Max D.
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US08/281,446
• Time in Patent Office: 895 Days
• Field of Search: 250/372 R, 250/372 EM
• US Class Current: 250/372
• CPC Class Codes: G01J 1/429 applied to measurement of ultraviolet light using counting tubes G01T

Abstract

A multipurpose all-wavelength intensity monitor for determining and monitoring the output intensity of ultraviolet sources. The unit measures ultraviolet wavelengths of 365 nanometers, 300-312 nanometers, and 254 nanometers without changing sensors or switches and the monitor is based on measurement utilizing a time period with a precalibrated microjuole setting. The intensity is determined by measuring the time period elapsed from the beginning of the monitoring to a tone sound which indicates the end of the monitoring period. This time period is compared to a chart with a curve for each of the ultraviolet wavelengths. Using the curve with the known time elapsed will indicate the intensity output. The monitor indicates loss of intensity by comparing lengthening of the monitored time or by indicating the actual intensity using the time output curves. A modified stopwatch can start the timing when unit is actuated and stop the timing when tone is sounded.

Claims

1. An electronic monitor for use with all ultraviolet wavelengths comprising:

(a) a first stage sensitive to all ultraviolet wavelengths providing a current proportional to the amount of ultraviolet exposure,

(b) a second stage coupled to said first stage operating as an integrator to establish a fixed constant in joules,

(c) a fourth stage coupled to the outputs of said first and said second stages constituting a comparator,

(d) a fifth stage coupled to said fourth stage constituting an oscillator supplying an activating signal to cause an audible tone indicating the end of cycle,

(e) a sixth stage which incorporates a modified stop watch to indicate the time elapsed from start of measurement to end of measurement, and

(f) a third stage operably coupled to said first, second, fourth, fifth and sixth stages providing power thereto and incorporating a voltage divider and supplying reference voltages.

2. An electronic monitor for measuring and indicating the strength of emitted ultraviolet rays comprising:

an ultraviolet sensor;

signal generator coupled to said sensor producing an output signal in response to activation of said sensor by ultraviolet rays;

a current-to-voltage conversion circuit connected to said signal generator receiving said output signal to produce a voltage signal;

an integration circuit coupled to said current-to-voltage conversion circuit responsive to said voltage signal to produce a reference voltage;

a timing circuit connected to said integrator circuit for establishing a time constant voltage;

a comparator circuit operably connected in parallel to said integrator circuit and said timing circuit responsive to said reference voltage and said time constant voltage to produce an operational voltage;

a stopwatch;

a beeper; and

said stopwatch and said beeper for receiving said operational signal simultaneously for operating said stopwatch and said beeper to indicate end of cycle.

3. The invention as defined in claim 2 including:

a feedback circuit coupled between said comparator circuit and said beeper.

4. The invention as defined in claim 3 including:

a gating circuit operably coupled to said comparator circuit;

a light emitting diode operably coupled to said gating circuit for emitting a light signal in response to said gating circuit for indicating beginning and ending of an operational cycle.