Switches Indicators & Gauges

Process control is a statistics and engineering regulation that deals with structural design, mechanisms, and algorithms for controlling the output of a specific process. General process controllers have always been high cost items, however, Semrad Pty Ltd have created the Unicont PM-300 series; universal process controllers incorporate at an affordable price.

Features

Features of the Unicont PM-300 series include:

• 2 universal inputs
• Up to 4 output relays
• RS485 modbus
• Autotuning
• 1000 alarm functions
• Auto tuning
• 32 point linearisation
• More than 1 million process configuration possibilities

The Unicont PM-300 series uses Modular design which guarantees short delivery times for the entire range. Unicont PM-300 series includes both PI and PID functions. This enables the control of both heating and cooling. It contains a 2-line, 4-digit bicolour display with a rounding system that can be manually defined for best results. A status indication is provided as well as high and low alarm set points to allow for optimal safety.

Data Loggers and Sensors

Water management sensors measure a range of variables such as water levels and precipitation amounts. They can use different technologies to determine measurements, whether by magnetostrictive, hydrostatic, air bubbler, vibration, rotating paddle, capacitance, optical, ultrasonic or microwave/radar. Sensors vary according to whether the substance being measured is a liquid, semi-liquid or solid. They can measure continuously or at specific points, such as at pre-determined points (such as when levels drop below or rise above certain points). 

The type of sensor used depends on the type of substance (i.e. liquid, semi-liquid, or solid), agitation or vibration, density, whether it must detect measurements in a vacuum or under pressure, the temperature, the type of container, the chemical composition of the substance, noise and so on.

Data loggers are electronic devices that record the data collected by the sensor. They are generally small, portable, battery powered and have a microprocessor and internal memory. Some data loggers interface with a remote computer and users then use software to view and analyse the data, while others have a local interface device (e.g. keypad and screen) so it can be used as a stand-alone device.

Combination Loggers and Sensors

Data loggers can receive data from external instruments and sensors, or can come built in with an internal sensor. Those with internal sensors are combination loggers and sensors. Semrad Pty Ltd offers a range of  WaterLOG® combination loggers and sensors:

• H-350-XL : a microprocessor controlled pressure sensor / data logger designed for remote operation. Interfaces with data loggers, chart recorders, GOES transmitters, remote displays and telemetry systems. Replacement for mercury manometres.
• H-350 : Pressure measurement system / manometer replacement including keypad display data logger using PCMCIA flash card and GOES radio options.
• DH-21 : H-310 sensor combined with logger and software.
• H-510 : Self-contained shaft encoder with SDI-12 data recorder.

Data Collection Platforms

First of all, what is ‘data’? Data is factual information, whether measurements or statistics used as a basis for reasoning, discussion or calculation, according to the Merriam Webster dictionary. A second definition is ‘information output by a sensing device or organ…that must be processed’, and finally ‘ information in numerical form that can be digitally transmitted or processed’.

A data collection platform is an electronic device that records data from a gauge and at pre-determined times transmits that data through a satellite to a remote computer. It refers specifically to weather devices, whether for complete automatic weather stations or similar hydrological setups. The gauge could be measuring precipitation, such as a rain gauge, or measuring pressure, or groundwater levels. So the gauge is connected to a data collection platform, possibly through an analog-to-digital converter, that then sends the measurements as data to a computer.

Microprocessor Data Loggers

Semrad Pty Ltd offers two microprocessor data loggers: the WaterLOG® Model H-350-XL and the WaterLOG® Model H-500-XL. The first is a controlled pressure sensor/data logger designed for remote operation, and the second is a data logger also for remote operation.

The H-350-XL model can be interfaced with data loggers, chart recorders, remote displays, telemetry systems and GOES recorders. Its key features include: easy to read digital displays that show the stage directly in engineering units, built-in temperature compensation and auto-zero functions, data logging capability using a non-volatile internal storage, four analog inputs, two programmable digital inputs/outputs, operating temperature range of -40° to 60°, a sealed, corrosion-resistant, non-conductive enclosure, and much more.

The H-500-XL model can also be interfaced with a range of data loggers, remote displays, modems, etc, and is ideal for small hydrologic and meteorologic stations. It features a built-in key pad, easy to read display that can be used for complete system configuration or to view measured variables, 2 programmable digital inputs/outputs, data logging capability, quadrature shaft encoder input, and more.