Single-beam photometer

Abstract

Abstract A SINGLE BEAM PHOTOMETRIC SYSTEM FOR DETERMINING THE CONCENTRATION OF A TESTED-FOR SAMPLE COMPONENT IN A SERIES OF INDIVIDUAL SAMPLE CELLS INCLUDES A CARRIER FOR MOVING THE INDIVIDUAL CELLS INTO THE MEASURING LIGHT BEAM, THE TRANSMITTED INTENSITY OF WHICH VARIES WITH THE CONCENTRATION OF THE TESTED-FOR COMPONENT. AN "EMPTY VALUE" REFERENCE LEVEL IS SET INTO THE INSTRUMENT BY POSITIONING A CALIBRATION CELL, IDENTICAL TO THE SAMPLE CELLS BUT WITHOUT THE SPECIFIC COMPONENT BEING TESTED FOR, IN THE LIGHT BEAM, AND ADJUSTING, FOR EXAMPLE, A VARIABLE POTENTIOMETER IN THE DETECTOR SIGNAL OUTPUT TO A 100% TRANSMISSION LEVEL. AN AUTOMATIC GAIN CONTROL TYPE OF FEED-BACK IS PROVIDED BY MONITORING A FIXED PROPORTION OF THE DETECTOR OUTPUT WHEN THE MEASURING BEAM PASSES BETWEEN EACH OF THE SAMPLE CELLS IN A SERIES (THE SAMPLE CELLS BEING SUFFICIENTLY SPACED APART FOR THIS PURPOSE). IN THIS MANNER, THE CORRECT "EMPTY VALUE" REFERENCE SIGNAL IS READJUSTED BETWEEN SUCH SAMPLE MEASUREMENT WITHOUT REQUIRING REINTRODUCTION OF AN ACTUAL CALIBRATION CELL OR ANY MANUAL STEPS. THIS AUTOMATIC GAIN CONTROL MONITORING MAY BE PROVIDED BY A FEEDBACK LOOP HAVING A SWITCH WHICH IS CLOSED ONLY DURING THOSE POSITIONS OF THE SAMPLE CELL CARRIER IN WHICH THE INTERMEDIATE SPACE BETWEEN CELLS IS IN THE LIGHT BEAM.

Inventors

• 👤 Peter Paatzsch
• 👤 Toma Tomoff

Bibliographic Details