Electricity + Control 2019

round up PRESSURE + LEVEL MEASUREMENT + INSTRUMENTATION

Efficient silo management it the choice of many plant operators, around the globe, who are faced with de- manding conditions. The Nivobob ® series of plumb bob sensors is used for contin- uous level measurement in bulk storage silos and for interface measurement. The simple electromechanical measurement principle is a reliable all-rounder for most bulk materials. In the Nivobob ® system UWT GmbH has developed an economical and practi- cal solution for centralised content level monitoring, especially suited for storage processes in industrial plants. The plumb bob system is mounted on each silo in the plant and the Modbus interface, supplied standard with the Nivobob ® 4000 series, allows for quick and easy connection of the units to the visualisation system. Parameters such as content level, operating time, pending replacement in- tervals and sensor status are available to the operator. The visualisation software Nivotec ® is used for level control, diag-

The electromechanical Lot system, Nivobob ® 4000, is equipped with a Modbus function which allows easy con- nection to visualisation systems, providing an economic silo management solution. With its advanced electronics techno- logy the electromechanical measure- ment device is a valuable instrument in inventory management. Nivobob ® is a reliable lot system and has a robust me- chanical design, features that have made

nostics and similar; information is sent from the electromechanical lot sensors to the visualisation system via Modbus. The operator can access the required information from any PC at any time. With its data storage and trend analysis functions the software enables the user to plan material disposition and required logistics. The outcome is efficient silo management which can deliver planning security and cost savings. With the Nivobob ® 4000 series UWT has responded to the demand for an af- fordable solution that combines reliable level monitoring with live-data visualis- ation for effective silo management. Morton Controls, specialist in instru- mentation and process control techno- logy, holds the agency in South Africa for UWT level monitoring and control systems.

Enquiries: Morton Controls. Tel: +27 (0)861 000 393, email: sales@mortoncontrols.co.za

Schematic illustrating the connected Nivobob ® 4000 system.

Accurate level measurement for groundwater and in tanks

overpressure sensor with a pressure-compensating capillary, can also be supplied for the DCX-18.The measurement data is stored in a non-volatile memory and the batteries are fast-charged every time data is extracted via the charging/read-out plug. Type DCX-22 AA level loggers (diameter: 22 mm) register and compensate for fluctuations in the local barometric pressure with

Instrotech offers Keller probes which can be used in a wide range of conditions to monitor groundwater levels and fill- ing levels in tanks. Depending on requirements, the probes can operate autonomously or they can be used with an in- tegrated data logger, wireless transmission (GSM), an ambi- ent pressure-compensating capillary, or a separate absolute pressure sensor. Additional options include integrated tem- perature measurement and other features. Depending on the sounding tube, probe diameters range from 16 mm to 18 mm up to 22 mm. With a diameter of only 16 mm, the DCX-16 can be used in locations where every millimetre counts (for sounding tubes with small diameters, for example). Type DCX-16 is screwed in position and is fully watertight.The unit operates as an autonomous battery- powered data collector with an absolute pressure sensor. The pres- sure sensor is welded into the logger housing. In shallow water, a second logger (barometer) can be used for separate recording of the barometric pressure on the surface. The differential pressure and/or the filling level are then calculated on the PC by subtraction of the time-stamped measurement data from the individual loggers. The fully-welded DCX-18 (diameter: 18 mm) is designed as an autonomous level logger, with rechargeable accumulator-type batteries, and provides for low-cost, long-term measurements of level and temperature.The microprocessor electronics compensate for linearity and temperature deviations by the pressure sensor, increasing the accuracy of the pressure and temperature signals. Different operating modes, with an absolute pressure sensor or an

a watertight air pressure sensor that is fitted on the top end of the sounding tube. The devices are resistant to conditions of use in a damp environment and will not even be damaged by brief flood- ing. The electronic equipment reg- isters the signals from the high- precision pressure and tempera- ture sensors, corrects linearity or temperature deviations according to a mathematical model, and then records the values to the internal memory. For standard operation, the built-in battery has a lifetime of 10 years. Enquiries: Instrotech. Tel: +27 (0)10 595 1831, or email: sales@instrotech.co.za

The Keller DCX-22 AA with air pressure sensor.

36 Electricity + Control

JUNE 2019