Greyline Instruments develops and manufactures industrial flow and level monitoring instruments for measurement and control in water and wastewater treatment, industrial process automation and for environmental monitoring. Greyline Level instruments include ultrasonic level transmitters, pump station controllers, tank farm monitoring systems, software and data loggers. Greyline's ultrasonic Flow products include portable meters for troubleshooting and surveys, Doppler flow meters with strap-on sensors, flow switches, open channel and area-velocity flow monitors.