Transducers are programmed with Hart hand-held calibrators or via PC interface. The measurement is represented either with 4 to 20mA proportional to the measurement value or using the Hart protocol. HART transducers are certified Atex zone 1 (Ex mb) without barriers. Atex zone 0 (Ex ia) on request requires a suitable barrier.
The HART transducers are current loop powered (3.8 ÷ 22mA) have IP68 protection for outdoor installations, are temperature compensated to increase accuracy and use version 7 of the Hart protocol with self-addressable transducers. Alternatively, they can be individually programmed using a suitable hand-held programmer or via PC. The first start takes 8 seconds, then if a typical 15-minute interval is used the start time becomes 3.5s. Terry Ferraris’ new transducers are compact, inexpensive and easy to install. They are designed for use on liquids or solids, and are reliably accurate and cost-effective. They are low-voltage instruments using the most advanced processor for echo analysis available, providing reliable and precise measurements.
The echo analysis software is able to distinguish, and ignore, obstacles, chains and ladders and follow what is moving inside the tank: Terry Ferraris’ dBi transducers have proven to work where other similar instruments have shown serious problems with functionality, reliability and repeatability.
dBi transducers are available in 4 types with a measuring range of 3/6/10/15m. They can be programmed using the standard communication protocols for the fieldbus type used or alternatively with Terry Ferraris SW. For use on solids, dBi transducers use an orientation coupling that, by directing the ultrasonic beam onto the body that is to reflect the echo, maximises the response, i.e. the reflected echo. Transducers convert level measurements into volume. The computer controlling the process has access to a library containing various pre-selected tank geometries that normally fit standard tanks, or it is possible to create a new volumetric geometry via SW by means of a dedicated level/volume table set up using a 16-point break.
The current output can optionally represent either the distance from the probe face to the target, or a level, space or volume. dBi transducers are available as Hart or Profibus PA devices in a wide range of models and executions to suit the installation, e.g. PTFE-coated flanged for use with corrosive liquids, foams or with threaded connections to facilitate mechanical installation in the field.