The new JULABO Circulator Program

Laboratory circulators are needed for basic research, materials testing, process chemistry, manufacturing and experimentation. The basic functional principles have changed little since the first electronic circulators were introduced at the beginning of the 1970s. However manufacturers have constantly widened their scope with several innovations. The development of more sophisticated technology has allowed complex applications to be performed. However, simple but practical solutions are still required for the majority of tasks. This is addressed by a new series of instruments that offer solutions to the most common demands.

Laboratory circulators have recently taken a large leap forward in terms of functionality. Digital electronics have enabled functions such as intelligent controllers, PC interfaces, integrated programmers and operation via keypad and display. Today almost all manufacturers offer models with these features. Yet often the user’s main problem can be quite different. Examples of this are a low liquid level alarm switch off during an experiment or a difficult to read temperature display. These factors are just as important to the everyday user as the technical specifications.

Julabo’s new circulator program addresses these and many other issues, offering functional solutions for everyday tasks, as well as future demands. The new instruments were developed by observing the following principles- no increase in price, no unnecessary technical gimmicks and the solution to familiar problems. The result is an instrument program that focuses on the needs of the user. No compromises have been made with these instruments. The new models offer more for the same price or better.

Three Product Series Simplify Choice

As with previous ranges, the new circulator program is divided into three model series (Pic. 1). From the Economy series of particularly competitively priced instruments through to the High Tech series there is a suitable instrument for every application. The Economy series has an LED display and keypad for input of the set points. The ME model is a great new addition to the TopTech series. This circulator has features that were previously found only in higher category models, such as Pt100 external sensor for measurement and control, Vacuum Fluorescent Display (VFD) with menu options displayed in clear text, integrated programmer, electronically adjustable pumps plus low level early warning system and RS232 interface. Truly a high-class product at a competitive price. In addition the High Tech series has intelligent cascade temperature control, individually designated connections for solenoid valves etc., RS485 interface, TCF Temperature Control Features and a powerful pump system with up to 1.1 bar capacity.

Overall the Julabo circulator program has become more concise. The instruments are functional and are easily differentiated according to the area of application. The choice of which model to purchase is now therefore much simpler. There are more than 100 model combinations available so every heating and cooling application is covered.

The new solutions in detail

One of the concepts for the new developments was to solve familiar problems. These are explained below in greater detail.

Low Liquid Level Early Warning System

The new early warning system for low liquid level solves an old, familiar problem with liquid temperature control. It is well known that bath fluids can evaporate in open systems. When a certain limit is reached the decrease in the liquid level triggers the unit to switch it self off. This function is a necessary requirement for safety reasons. However this shut down can cause problems in long-term applications. If this happens the process is stopped abruptly, the work will have been in vain, and often an expensive experiment is ruined. The new early warning system gives a visual and audible warning as soon as the liquid level reaches a critical point. The warning is also given via the serial interface. The instrument will be switched off only if the warning is ignored (Pic. 2). This gives the user sufficient time to refill the bath fluid, ensuring that work can continue without interruption.

Everything at a glance on the VFD-Display

An additional new feature is the (VFD – Vacuum Fluorescent Display). This illuminated display is clearly visible from long distances, in poor light and at any angle (Pic. 3).

The unit settings are shown in clear text directly on the display, providing easy operation without the need for an operating manual. The three most important temperature values (set point, actual internal and external temperatures) as well as status information are displayed simultaneously. Warning and alarm messages are also clearly visible on the display and colour symbols give information on all the important operating conditions. This VFD-Display has a large advantage over high resolution but difficult to read graphic displays.

Visualisation and Documentation

It a lot of cases measurements will be evaluated via a PC. For this purpose, Julabo offers free ‘EasyTemp’ software that enables recording, visualisation and data logging of measurements via the RS232 interface. An optional adapter is needed for connection to an USB interface. If the circulator is connected to a PC or laptop, it can also be controlled remotely via the serial interface. The ‘EasyTemp’ software supports all-important functions such as Start, Stop, Set point, Programming and Display Actual Value etc. This is particularly useful when the circulator is used for closed systems.

Flexibility with adjustable pumps

The new electronically adjustable circulation pumps bring greater flexibility and additional advantages. The pumps can be adjusted in stages, so the pressure and flow rate is tailored to the application. For example, for applications inside the bath, the circulation can be reduced to prevent unwanted turbulence and for external applications, a higher level can be selected to give optimum pressure and flow rate capacity.

The pump capacities of these new series models are clearly superior (Pic. 4). The Top Tech series now offers a pressure capacity of 450mbar and a flow rate of 11-16 Lpm. The High Tech series can reach 1.1bar and 22-26 Lpm. This is a big advantage for large volume applications, applications at different elevations or with long tubing connections.

Intelligent Electronics Save Time

The electronics perform many of the functions automatically, enabling the user to concentrate on his work. The self-optimising ICC temperature control (ICC-Intelligent Cascade Control) automatically tailors the control parameters to the application. The user does not have to worry about setting complicated control parameters but still gets the very best results. All the relevant factors for control behaviour have been incorporated into a single TCF (Temperature Control Features) concept. This means total control plus the ability to manually optimise the features to your requirements.

The integrated programmer, which features in the ME model, as well as in the High Tech units, enables time-controlled processes. Temperature processes can be started or stopped during user absences using the real time clock. This enables advance heating up and cooling down of the system.

Another new feature is the ATC3 3 point calibration (Absolute Temperature Calibration). This allows for manual correction of a temperature differential within the system. This function is particularly important for calibration applications and allows the unit to be used as a testing instrument according to DIN/ISO 9000. ATC3 enables simultaneous calibration to three preferred measuring points.

Retrofitting on demand

The High Tech series models are now supplied with digital interfaces as standard and analogue connections are available as an option at time of purchase or as a retrofit at any time. The advantages of this are obvious- you don’t pay for what you don’t need. If analogue inputs/outputs are required, just plug in the electronics module (Pic. 5). This retrofit module will accept all signals to and from a temperature recorder, external programmer, stand by or alarm. The plug in module is quickly and easily mounted as shown and is independently recognised by the instrument.

Conclusion

The new circulator program offers many practical benefits. Familiar problems with everyday temperature control applications are solved thanks to our innovative features. Quality and reliability remain at the highest level whilst operation of the instruments is much simpler. Best of all the new units offer all these additional features and a greater performance at no extra, or even less, cost than before.