The Rosemount 3100 Series ultrasonic level transmitter is a liquid level transmitter based on ultrasonic technology
that is suitable for many liquid applications. The Rosemount 3100 Series ultrasonic level transmitter is simple to
set-up and operate. Once installed, maintenance is minimal. Non-contacting measurement with no moving parts
eliminates the problems typically experienced with contacting instrumentation. The Rosemount 3100 Series ultrasonic
level transmitter features 2 integral signal relays, corrosion resistant PVDF wetted material, simple push button
programming, automatic temperature compensation, and a built-in LCD display.
The entry-level Rosemount 3101 ultrasonic level transmitter is designed for simple level or distance measurements
over a range of 1 to 26 ft and a 4-20mA signal output.
The Rosemount 3102 ultrasonic level transmitter has two integral relays for level or distance measurements over a
range of 1 to 36 ft. It also features volume and open channel flow calculations and a 4-20mA / HART output.
The Rosemount 3105 ultrasonic level transmitter is intrinsically safe for use in hazardous areas. HART digital
communications are also provided. With a PVDF wetside, the Rosemount 3105 ultrasonic level transmitter can be used
in most hazardous and corrosive applications. Apart from the integral temperature sensor, an optional external
temperature sensor may be used with the Rosemount 3102 and 3105 ultrasonic level transmitters, which may be used
to measure distance and level or calculate volume or flow in an open channel.
Ultrasonic Measurement Principle
Ultrasonic pulse signals are transmitted and reflected from the liquid surface. The transmitter 'listens' for
reflected signals (echoes) and measures the time-delay between transmitting and receiving. The distance to the
liquid surface is automatically calculated using the computed time-delay. An integral temperature sensor
continuously measures the air temperature around the transmitter. It then computes the speed of sound in air,
automatically compensating the distance for temperature effects. The 3102 and 3105 have a remote temperature
sensor option. The distance measurement can be sent through the 4-20 mA or HART ® output.