OPERATION MANUAL MiniStirrus MAGNETIC STIRRER/HEATER VP 706B-4H

Transcription

1 OPERATION MANUAL MiniStirrus MAGNETIC STIRRER/HEATER VP 706B-4H TECHNICAL NOTE 275 Horizontal Heat & Stir Deck Power Switch (in back) Programmable Temperature Control Heater Control Switch Speed Control Knob Stirrer Control Switch Fig. 1 VP 706B-4H MiniStirrus Magnetic Stirrer/Heater shown with 5000mL bottle (not included) Pacific Heights Boulevard, Suite T, San Diego, CA (858) Fax: (858) sales@vp-scientific.com

2 WARNING!!!!! Be advised that the VP 706B-4H MiniStirrus Magnetic Stirrer/Heater has very strong magnetic fields coming from a 48 MGO Neodymium Iron Boron magnetic drive magnet. People with pacemakers should not get closer than 24 inches. Remove all magnetic influenced tools and objects from the immediate area to prevent them from being pulled onto the magnet or from striking anyone as the objects are pulled towards the magnet. Keep credit cards, watches and other magnetic sensitive items at least 24 inches from the Magnetic Stirrer s magnetic fields. Do not operate the MiniStirrus in the close proximity to thick pieces of aluminum or ferromagnetic material. When preparing to mix in a glass container, add stir bar when container is not on the MiniStirrus Magnetic Stirrer/Heater. OPERATION We recommend that the MiniStirrus be installed as far away from ferromagnetic material as possible. The closer and larger the magnetic material is to the MiniStirrus, the greater the torque that is required and the slower the maximum speed will be. Placement on a study bench top or table is also recommended. Thick aluminum or steel table tops, as well as racks or holders, should be avoided. Although aluminum is not magnetic it will cause a drag on the magnetic field due to eddy currents being formed when magnetic flux lines pass through it. A large mass of aluminum will cause a significant drag and result in lower motor speed, and will generate heat in the aluminum object. Also, the MiniStirrus can only support up to 110 pounds. POWERING UP The VP 706B-4H is driven by a powerful electric motor with a speed range of 100 to 2000 RPM. The actual top speed will depend on the load (i.e. the volume and or the viscosity of liquid to be stirred). Use the following procedures to start the motor and adjust speed: 1. Make sure the power cord is inserted into the plug in the back of the instrument. 2. Turn on the AC Power Switch located on the back of the magnetic stirrer. The switch will illuminate and the ventilation fans will turn on. 3. Operating the magnetic stirrer: a. Turn on the Stirrer Control Switch. Turn the Speed Control Knob clockwise. The magnetic drive magnet will begin to rotate. b. To increase the speed, continue to turn the Speed Control Knob clockwise. c. Turn counter clockwise to decrease the speed. When the Speed Control Knob is turned all the way down (counter clockwise), the drive magnet will come to a complete stop. d. It is not recommended to stir at speeds lower than 100 RPM (Optional RPM meter, VP 710RPM, is available). 4. Operating the heat plate: a. Turn on the Heater Control Switch. b. Display will illuminate. Lower green numbers are the setpoint temperature while upper red numbers are the current process temperature. c. Adjust the setpoint by pressing the up/down arrows below display. d. Heater will immediately turn on to go to the set temperature. e. Turn off the Heater Control Switch to turn off heat plate. It is recommended to allow the fans to run for a period of time after heater is turned off. 5. Turn off AC Power Switch when not in use. V&P Scientific, Inc. 2 Technical Note 275

3 STIRRING VESSEL PLACEMENT The VP 706B-4H was designed to accommodate vessels of a variety of sizes with various types of stir elements. It is recommended that the vessel be centered to the middle of the instrument deck as marked by the rings. Use of vessels with diameters larger than the MiniStirrus deck is not recommended. OPERATING SPEED The operating speed of the MiniStirrus is application dependent and needs to be determined empirically. Once the optimal stirring speed has been determined, note the number on the display or leave the speed set to that number when powering down. Factors to consider in determining optimal stir speed are the fragility of the objects being stirred, size, shape and depth of the vessel, volume and viscosity of the liquid and the type of Stir Element used (such as whether they are stainless steel, Alnico, Samarium Cobalt, Neodymium, or Neodymium Sandwich style). To stir very viscous solutions, start at a low speed, and then ramp up slowly to the desired RPM. The strength of the MiniStirrus s magnetic field allows it to obtain speeds higher than conventional magnetic stirrers because of the greater magnetic coupling of the drive magnet to the stir bars or stir elements. In general, stirring microbial cultures works best at low speeds. Stirring to re-solubilize extracts or to stir in deep well micro-plates requires high speed. Again, the speed of stirring needs to be determined empirically for each particular application. A RPM meter, VP 710RPM, is available to measure the speed. NOTE: Use of V&P Scientific s Neodymium stir bars is recommended due to greater magnetic coupling between these stir elements and strong drive magnet in the stirrer. Figure 2. Examples of various shapes and sizes of V&P Scientific magnetic stir elements available for use on the MiniStirrus V&P Scientific, Inc. 3 Technical Note 275

4 OPERATING HEAT PLATE CAUTION: Entire top of magnetic stirrer will be hot when heater is turned on, exercise caution when placing container to be stirred on stir/heat deck. Operating the heat plate controller is as simple as setting the setpoint using the up/down arrows on the control panel. Although the center of the heat plate will be at the temperature on the display, the actual temperature of the liquid being stirred will be below this temperature depending upon the efficiency of heat transfer. It is recommended that the temperature of the liquid be measured to determine appropriate setting for a particular application. The heat plate is calibrated with an external temperature probe so that the temperature on the display is that of the surface of the heat plate. It is recommended the calibration procedure be performed routinely. To perform a calibration, place an accurate thermometer or temperature probe on the surface of the heat plate. Set the temperature setpoint to a given temperature. Allow the heat plate to reach the setpoint and stabilize. If external temperature is different than the reading on upper display of controller, make calibration off-set adjustment by changing the Shift/Offset parameter in the controller. The following are the steps to accomplish this (please refer to pages 7-11 of the Red Lion Controller Instructions for more details): 1. The Shift/Offset parameter (SHFt) is found in the Input Parameter Menu (I-In), which is accessed by stepping through the Hidden Loop to the Configuration Loop (CnFP). 2. On the controller press the advance key [ ] and hold for 3 sec to access the Hidden Loop. 3. Then press the advance key 5 more times until the Configuration Loop is reached (CnFP/nO). (Pressing advance key one more time will return to the Display Loop.) 4. Press the up arrow to enter the Input Parameter Menu (I-In). 5. Press the advance key to step through the parameters: Red Green type r385 SCAL oc dcpt 0.0 FLtr 4 SHFt 0.0 SPLO SPHI 25.0 FIIn none 6. When Shift/Offset parameter (SHFt) is reached, make adjustments with up/down arrows to change value to make heat controller display temperature match external temperature reading. 7. After last parameter Configuration Loop is reached (CnFP/nO). 8. Press advance key again, End appears and controller is returned to the Display Loop. The upper limit temperature on the heat plate controller is set to 120 o C at the factory. Temperatures higher than 120 o C should not be used with polypropylene containers. Polypropylene will melt at temperatures greater than 130 o C. To operate at temperatures above 120 o C, use of glass or other high temperature-stable containers is recommended. To increase the maximum temperature beyond 120 o C, perform the previous steps used for the calibration procedure and change the values for the Setpoint High Limit (SPHI) parameter. This can be done for the Setpoint Low Limit (SPL0) parameter as well. V&P Scientific, Inc. 4 Technical Note 275

5 GENERAL PRODUCT CARE When not in use, turn the AC Power Switch off. CARE To clean the deck of the MiniStirrus, which is made of anodized aluminum, please use a mild detergent and wipe with a damp cloth. Do not use abrasive materials to clean. Do not place the unit in chambers with temperatures above 40 o C. Do not allow liquids to get into the inside of the MiniStirrus. The MiniStirrus motor is a brush motor and requires no maintenance. If technical assistance is required, please contact: V&P Scientific, Inc Pacific Heights Blvd., Suite T San Diego, CA Phone: Fax: sales@vp-scientific.com. WARRANTY V&P Scientific, Inc. warrants this product to be free from defects in material and workmanship when used under normal laboratory conditions for one year. This warranty begins from the date of delivery by V&P Scientific. In the event this product fails under normal laboratory conditions within the specified period of time because of a defect in material or workmanship, V&P Scientific will, at its option, repair or replace the product. Damage to the product caused by user negligence is not covered. Please keep the special shipping carton in case the unit needs to be shipped back to V&P Scientific. Please contact V&P Scientific at the address below for return authorization and shipping instructions. This warranty is made in lieu of other warranties expressed or implied including the warranties of merchantability and fitness for a particular purpose. V&P Scientific shall not be liable for loss or damages arising from the use of these products nor for consequential damages of any kind. V&P Scientific, Inc. 5 Technical Note 275

6 SPECIFICATIONS AND CAUTIONS The VP 706B-4H MiniStirrus Magnetic Stirrer/Heater is driven by a 24 VDC motor. This motor was selected primarily because of its ruggedness and reliability. If the equipment is used in a manner not specified by V&P Scientific, Inc., the protection provided by the equipment may be impaired. The use of motor controls, like that of all utilization of concentrated power, is potentially hazardous. The degree of hazard can be greatly reduced by proper design, selection, installation, and use, but all hazards cannot be completely eliminated. The following safety precautions must be observed during all phases of installation, operation, service, and repair of this motor control product. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture and intended use of the products. V&P Scientific assumes no liability for the customer s failure to comply with safety requirements and practices. Note the following WARNINGS and CAUTIONS associated with the MiniStirrus. A WARNING will highlight a procedure, which presents potential danger to people, and a CAUTION will highlight a possible danger to equipment. Both types of instructions must always be followed. WARNING Do not touch the amplifier or components on the PCB right after turning off the power. Wait until the power indicator turns off or at least seven minutes. Do not attempt to wire circuitry while power is on. Do not attempt to examine the components and signals on the PCB while operating. Do not attempt to disassemble or modify internal circuitry, wiring, or components. The grounding terminal must be grounded properly with 200V class type III standard. Do not remove the cover of the motor case when the power is ON to avoid personnel injury caused by electrical shock. CAUTION Do not attempt a dielectric strength test to internal components. They are sensitive semiconductor-devices vulnerable to high voltages. Do not connect the output terminals to an AC power outlet. Do not disconnect motor during operation. Otherwise, overcurrent breakdown may result. V&P Scientific, Inc. 6 Technical Note 275