Emerson Process Management”s Mobrey MSP900 ultrasonic level transmitter is designed for use in open-channel flow measurement. The new MSP900FH features a pre-wired, remote temperature sensor and is a good fit for water and industrial processing sites looking to improve the accuracy of their open-channel flow measurements. Used in the open air, conventional ultrasonic level transmitters are prone to suffer from inaccuracies caused by “solar gain” when the sun shines directly on them. The Mobrey MSP900FH transmitter has been designed to overcome this problem by using a remote temperature sensor wired directly into the transmitter. Measuring just 10mm diameter x 25mm length, the compact sensor can easily be located in an appropriately shady spot between the liquid surface and the transmitter. In this way, the system ensures the air temperature measurement used in the speed of sound calculation is truly representative. The sensor is hard-wired into the transmitter with a two-meter cable, so there is no additional cabling or setup required, and only a single connection to the controller, thus keeping installation costs to a minimum. The transmitter is 24V DC loop-powered, with a waterproof housing sealed to IP68 specifications. It has both analog 4-20mA communications and digital HART options built-in, and it can be used stand-alone or as part of a site-wide measurement, control, and data acquisition system.