APPLICATIONS
Emtivac understands the importance of having good instrumentation to ensure that procedures are carried out to specification, vacuum equipment is performing correctly, process criteria's are met and repeatability can be guaranteed. For this reason Emtivac has selected Thyracont for their high quality German engineered and manufactured absolute vacuum gauges, vacuum controllers and other vacuum instrumentation.
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| Vacuum Furnances Vacuum Drying |
Laboratory Chemistry |
Maintenance of Pumps and Appliances |
Electronics Semiconductors |
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| Coating Vaporization |
Analysis Spectromitry |
Evacuation Charging |
Packing Isolation |
Vacuum Furnances, Vacuum Drying
Application Example Vacuum Furnaces
Brazing, sintering or annealing of metals require an atmosphere free of oxygen. Therefore such processes are carried out under vacuum, partially using inert gas.
Challenge
The vacuum level must be monitored and kept constantly low during the process in order to avoid oxidation of the products. Our client had to measure the pressure in his high vacuum tube furnace near the gas inlet as well as at the vacuum port with high accuracy.
Solution
Two VSH82MV transducers have the required wide measuring range and detect the pressure at the furnaces gas inlet and vacuum port with excellent precision. They are linked to the system PLC by their serial RS485 interfaces, so that both pressure levels can be directly visualized in a diagram. This allows for easy monitoring the pressure gradient inside the furnace tube.
Application Example Freeze Drying
Freeze drying is a method for carefully extracting moisture from products like food or serums. Such products are sensitive to temperature and care has to be taken in order to protect their internal structure. Freezing is followed by an accurately controlled pressure decrease, which leads to sublimation of the microscopic ice crystals.
Challenge
Losses of expensive product lots must be avoided and process run at reasonable cost. This is why the demands on the required vacuum gauges regarding repeatability and reliability are extremely high.
Solution
The VSP62MV Pirani is protected against vapour condensation by a stainless steel shield. Its metal sealed sensor with long-life helix filament and the stainless steel flange make the gauge especially robust. The results are an improved reliability of the process and a decrease of maintenance costs.
back to the topLaboraty Instruments, Chemistry
Application Example Rotary Evaporator
The recovery of solvents in laboratories has established itself as common practice for the reason of cost and environmental protection. In rotary evaporators such solvents are boiled under vacuum at moderate temperature to save time and energy. The solvent vapour liquefies in a water-cooled condenser and is collected in a flask.
Challenge
During the distillation the absolute pressure in the evaporator must be controlled accurately. Undershooting the boiling pressure results in foaming and ebullition of the solvent mixture, so that the distilled solvent gets contaminated. Bumping and an irregular boiling process make extreme demands on speed and precision of the pressure controller.
Solution
The DC1S vacuum controller with proportional valves for vacuum and venting regulates the process pressure inside the evaporator carefully and with high accuracy. A powerful Fuzzy control allows for rapid reaction to fluctuating amounts of vapour and guarantees a sharp approach to the boiling point. With its automatic mode for finding boiling points and soundless valve operation the controller offers exceeding comfort for laboratory use.
Application Example Chemical Engineering
In chemical engineering inflammable solvents with high vapour pressure are frequently used. Together with air they can build explosive composites.
Challenge
When oxygen-sensitive products are treated in laboratory reactors, the process is usually carried out under vacuum or inert gas atmosphere with well defi ned pressure. However, pressure must not fall below aspecific limit since many of those substances tend to bumping.
Solution
The VD82EX vacuum meter is certified according to ATEX II 2G EEx ia IIC T4 for use in explosive areas. With this instrument the pressure inside the flask or reactor can be measured reliably and safely no matter what kinds of inflammable vapours may be present.
back to the topMaintenance of Pumps and Appliances
Application Example Maintenance of Vacuum pumps
Systematic maintenance and servicing of vacuum pumps helps to prevent breakdowns in production and improves the availability of the system.
Challenge
For diagnosis of the pump as well as for executing maintenance work the achieved minimum pressure and the pump-down characteristic have to be recorded. These factors provide essential information about the actual condition and performance of the pump.
Solution
A VD85M with wide range combination sensor is capable of capturing the minimum pressure of many pump types like diaphragm, scroll or rotary vane pumps. In addition the instrument can measure and -on demand- record the complete pump-down cycle from atmosphere to end pressure. In this case the vaccum meter is used as datalogger which stores the measurements in the internal data memory. Via serial interface those data can then be transmitted to a PC for further analysis and documentation.
back to the topElectronics and Semiconductors
Application Example Wafer Bonding
Wafer bonding is a procedural step in semiconductor technology, where two wafers are joined. For certain applications like the encapsulation of chip sensors this process is carried out under vacuum.
Challenge
When loaded the bond chamber is evacuated in a bypass connection by means of the roughing pump until a vacuum level is reached, where the system can be switched smoothly to the high vacuum pump. The bonding process is then performed under high vacuum conditions. Absolute pressure in the bypass-line must be accurately controlled during evacuation in order to prevent damaging of the high vacuum system. During the wafer bonding the vacuum inside the chamber has to be monitored to guarantee the required results.
Solution
A type VSC42MA4 rough vacuum transducer is used for controlling the bypass cycle. Its ceramic sensor measures the absolute pressure with the required accuracy and is nearly maintenance-free. The process pressure of the bonding procedure is monitored by means of a VSM72MV vacuum transducer with Pirani/Cold Cathode combination sensor.
back to the topCoating and Vaporization
Application Example Optical Coating
During the optical coating of mirrors for laser resonators the typical process pressure lies above 2 x 10-3 mbar.
Challenge
A suitable vacuum transducer must be able to monitor both, process pressure during the coating as well as the available minimum pressure of 10-6 mbar in the vacuum chamber. Our client used to work with a Pirani/cold cathode combination gauge, the cold cathode monitoring minimum and process vacuum. However, the continuous operation above 10-3 mbar resulted in early wear and tear of the sensor.
Solution
In the VSM72MV vacuum transducer a patented impulse Pirani with extended range activates the cold cathode only below very low pressures. Further the transition between the two sensors can be configured according to the applications requirements. This way we achieved that the entire coating process is now monitored by the Pirani. The cold cathode is saved because it is active only when the appliance pumps down to minimum pressure. The availability of the coating plant improves significantly.
back to the topAnalysis, Spectromitry
Application Example Carbonated Beverages
Carbon dioxide gas is used for the industrial production of carbonated beverages. This extends shelf life and the beverage tastes fresh and sparkling.
Challenge
Because the gas gets in contact with many different substances during its fabrication, the end product can still be flawed with rests of contamination. To assure proper quality of the carbonated beverage production it is essential to monitor the pureness of the carbon dioxide by means of a spectrometer alignment. Since detection limits for gas components like carbon monoxide, methane or hydrogen sulphide usually are in the range of less than 0.01 ppm the spectrometers must operate with high accuracy and reliability.
Solution
Periodic offset adjustment under fine vacuum conditions guarantees that even slightest hints of contamination can be detected. The precise VSP62MV Pirani vacuum transducer controls whether the required vacuum level for zero adjustment is achieved. With its elastic helix filament and the rugged metal housing the transducer is especially durable.
back to the topEvacuate and Charging
Application Example Refrigerators and Air Conditioners
Refrigerators, air conditioners and cooling machines operate according to a thermodynamic cycle process, in which heat is transferred from the cooling cabinet to a warmer surrounding.
Challenge
As transport medium fort he heat a refrigerant is used inside the closed cycle cooling system. Before this cooling system is filled or when it is to be refilled after maintenance work it first has to be completely evacuated to approx. 10-3 mbar, so that no rest of air or air humidity remains in the system. This would reduce the capability of the appliance and may even lead to serious damage of the cooling system. Further care must be taken thet there are no leaks in the system. Therefore the vacuum level which is reached after evacuation has to be checked accurately.
Solution
Compact vacuum meters of type VD84M/2 with external Pirani sensor measure the vacuum inside the cooling system with appropriate accuracy and resolution. The handy gauges are easy to operate and are optimal for use in the service and maintenance. Via an optional serial interface the measurements can be stored and analyzed on a PC.
Packing Isolation
Vacuum packaging increases storage life of food products by a factor 3 to 5. For that purpose the package is first evacuated and then hermetically sealed.
Challenge
The correct functioning of the packing machine must be checked regularly. Only when there is sufficient vacuum inside the packing, quality, freshness, nutrients and taste of the product is fully maintained.
Solution
A battery operated VD81MC is put into the packing machine in defined time intervals and vacuum-sealed instead of the product. During the packaging process the instrument stores the achieved minimum pressure. After the vacuum meter is taken out of the packing this minimum pressure can be displayed and checked.
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