Apparatus for testing gas, liquids and solids; optical sensors; sensors for measurement purposes, other than for medical use, namely, sensors for measuring distance, chemical levels in aqueous solutions, not for medical use; non-contact measuring apparatus for measuring distance and liquid levels, namely, distance measuring apparatus and liquid level sensors; water quality meters, namely, electronic-based instruments for measuring water quality; water quality measuring apparatus, namely, scie...

computer services, namely, providing on-line access in the field of pipeline service information for the transmission of natural gas