Karishma Instruments Pvt. Ltd. Supplies Ozone Meter for Gases. Karishma Instruments Pvt. Ltd. Manufactures Laboratory Turbidity Meter, On-line Turbidity Meter, Fluorescence Meter, and Absorption Meter etc. The Ozone Meter for Gases is built to accommodate up to three different light sources [UV and visible range] for the measurement of colour, DOC and concentrations [Ozone].