9 analytical electrical measuring instruments, namely, photometric analyzers and computer software incorporated therein and accessories therefor, namely, cuvettes, pipettes, and associated laboratory ware, for use in the detection and measurement of environmental parameters, including BOD (Biochemical Oxygen Demand), COD(Chemical Oxygen Demand), TOC (Total Organic Carbon), TSS (Total Suspended Solids), nitrates, ammonia and surfactants in liquids and solids