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J-KEM Scientific Gemini User Manual

Temperature control for research and industry
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Temperature Control For Research and Industry
Gemini
User's Manual

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Summary of Contents for J-KEM Scientific Gemini

  • Page 1 Temperature Control For Research and Industry Gemini User’s Manual...
  • Page 3 Warranty J-KEM Scientific, Inc. warrants this unit to be free of defects in materials and workmanship and to give satisfactory service for a period of 12 months from date of purchase. If the unit should malfunction, it must be returned to the factory for evaluation. If the unit is found to be defective upon examination by J-KEM, it will be repaired or replaced at no charge.

  • Page 4: Table Of Contents

    INDEX SECTION PAGE 1. QUICK OPERATING INSTRUCTIONS ..... . 4 KEM-NET DATA LOGGING AND CONTROL SOFTWARE ..5 2.

  • Page 5: Quick Operating Instructions

    See Appendix II. NOTE: The Gemini has 2 completely separate temperature controller in a single cabinet labeled “Channel 1” and “Channel 2”. Any change or adjustment made to Channel 1 will have no affect on Channel 2 and visa versa. The instructions below apply to each channel individually.

  • Page 6: Kem-Net Data Logging And Control Software

    KEM-Net Data Logging and Control Software At the beginning of 2008, J-KEM implemented a redesign of it’s research grade temperature and vacuum controllers. The redesign involved both the hardware running your controller and software for remote control and data logging. Hardware –...

  • Page 7: Adjusting The Controller For Stable Control With Different Heaters

    Adjusting The Controller For Stable Control With Different Heaters The Gemini controller has 2 completely independent temperature controllers in one cabinet. It's important to remember that changes made to Channel 1 have no effect on Channel 2 and visa-versa. Each channel must be tuned and adjusted separately.

  • Page 8: Autotuning Procedure

    It’s important to understand that this controller isn’t a simple ON/OFF type controller (i.e. ON when below the set point, OFF when above [though it can be made to work this way, see Section 3.12]). Rather it’s a predictive controller. Based on the shape (slope) of the heating curve, the controller predicts (calculates) the percent of power to apply to the heater now to control the shape of the heating curve minutes in advance.
  • Page 9 New tuning Temp values loaded into memory Point Heat to set point The autotune sequence. after entering new parameters During autotune the controller heats to 75% of the set point temperature 75% of where it oscillates for several cycles set point before loading the new tuning parameters.

  • Page 10: Tuning For Heating Mantles: A Special Case

    Autotune Errors. The autotune routine can fail for several reasons. If it fails, the controller displays the error message “tunE” “FAiL”. To remove this message turn the controller off for 10 seconds. Try the procedure titled “Autotuning the Controller for Very Fine Control” above. If autotune fails again, call and discuss your application with one of our engineers.

  • Page 11: Operations Guide

    Section 3: Operations Guide Front Panel Description. 20 (on back) 10 11 Figure 1 Channel 1 Temperature Display. Shows temperature of the process connected to Channel 1 as the default display. Shows set point temperature (i.e. desired temperature) when ‘ * ’ button is held in. Channel 2 Temperature Display.

  • Page 12: Heater Restrictions

    Channel 2 Power Level Selection. This button is the interface to J-KEM’s patented power control computer which limits the maximum power delivered to the heater. See Sections 3.6 and 4.1. Channel 1 Power Level Selection. This button is the interface to J-KEM’s patented power control computer which limits the maximum power delivered to the heater.

  • Page 13: Ramp-To-Setpoint & Soak Feature

    Ramp-to-Setpoint & Soak Feature. A new feature of J-KEM’s controllers called ‘Ramp-To- Setpoint’ allows you to enter a specific heating rate (e.g., heat to 120 C at a rate of 5 C/Hour), a second feature called ‘Soak’ then lets you specify how long to stay at that temperature before turning off. Examples of Program Ramps Soak Ramp...
  • Page 14 Important Points to Know While the Ramp-to-Setpoint feature in activated, the display alternates between the current reaction temperature and the word “SPr” to indicate that a “SetPoint Ramp” is active. Channel 1 of this controller is equipped with a digital 100 hour timer, the digital timer and the Ramp- to-Setpoint feature are completely independent of each other.

  • Page 15: Over Temperature Protection Circuit

    Over Temperature Protection Circuit. follow Procedure 3 below. Both channels of the Gemini are equipped with over temperature protection circuits. This circuit turns off heating and sounds an audible alarm if the process temperature for Channel 1 and/or Channel 2 exceeds the set point by 5 degrees.

  • Page 16: Timer Controls

    The 100 hour timer works with Channel 1 only, it has no effect on Channel 2. Timer Controls The timer section turns outlet 9 either ON or OFF in an unattended operation when the time in the counter expires. To enter a value into the timer press the [UP arrow] or [DOWN arrow] buttons (19) to increase or decrease the displayed time.

  • Page 17: Temperature Sensor Input

    Example Power Setting Explanation 80 ml toluene 50 - 500 ml ≈ o C are set to the volume Organic solvents heated to 50 - 110 100 ml flask (25% power) range on the front panel. When choosing between 2 power 100 ml heating mantle settings (i.e.

  • Page 18: Affect Of Power Setting On Heating Profile

    Affect of Power Setting on Heating Profile. The following graphs show the affect of selected power levels on heating performance in a variety of situations. Each example contains 1 optimal and 1 or 2 less optimal settings demonstrating use of the output power level. Graph 1 This graph shows typical Conditions: Set point = 75 C...

  • Page 19: Do's And Don'ts When Using Your Controller

    Set point = 155 C Graph 3 Power = > 2 L (100% power) Another factor affecting the choice of power setting is the set point temperature. For set points near room temperature a low Set point = 100 C Power = 300 ml - 2 L power level is adequate.

  • Page 20: Resetting The Controller For Use With Heating Mantles

    3.10 Resetting the Controller for Use With Heating Mantles. If you want to use your controller with heating mantles after it’s been tuned for a different style heater, rather than autotuning the controller with the heating mantle, J-KEM recommends that the controller be manually tuned by following the procedure below.

  • Page 21: Changing Between Pid And On/Off Operating Modes

    3.12 Changing Between PID and ON/OFF Operating Modes. The controller can heat in either of 2 operating modes, PID (Proportional, Integral, Derivative) or ON/OFF mode. The difference between them is the way they supply power to the heater. In ON/OFF mode (the simplest heating mode), the controller is ON when it’s below the set point and OFF when above.

  • Page 22: Troubleshooting

    3.13 Troubleshooting. Corrective Problem Cause Action Large over shoot of the set Output power level is set too high. Set the output power level to a lower setting (see Section 3.6). point (Make sure you’ve set the power (> 3 o ) during initial warm-up or level for the channel actually being used).
  • Page 23 Displayed temperature is The controller has not warmed-up. The display temperature reads low when the controller is first incorrect. turned on, but will self-correct as it warms up. The controller can be used immediately since it will warm up during the initial stages [Note: Types ‘K’...

  • Page 24: Application Notes

    Section 4: Application Notes Supplemental application notes on the following topics are available by contacting J-KEM. Application Note Subject How to heat oil baths with your controller. (Included in Appendix) Changing the controllers thermocouple type. Changing the heating outlet into a cooling outlet. Using the controller for unattended fractional distillations.

  • Page 25: Controlling A Heating Mantle Temperature Directly

    Imagine heating a gallon of water to 80 C in a 5 quart pan on an electric range. Placing the pan on the range and turning the heat to ‘high’ you’d observe a delay in heating while the range coil warmed- up.
  • Page 26 Procedure 4 in Section 3.10 will program the controller for heating mantles. For all other heaters, see tuning instructions in Section 2.

  • Page 27: Automatic Storage Of Min/Max Temperatures

    Heating Power After the controller is reprogrammed, place a fine gage wire thermocouple Mantle Size Level ≈ ( 1/3 the size of kite string; available from J-KEM) in the bottom third of 5 & 10 ml 1-10 ml the heating mantle and fit the flask snugly on top so that the thermocouple 25 ml 10-100 ml 50 ml - 22 L...
  • Page 28 Table 1 Tuning Parameters for Various Heaters Fill in values determined for your equipment for quick reference. Proportional Integral Time Derivative Time Derivative Band (Reset) (Rate) Approach Cont. Cycle Time “bAnd” “int.t” “dEr.t” “dAC” “CyC.t” Instrument Heating Mantles (Factory Default) Heat Lamp Oven Vacuum Oven...

  • Page 29: Appendix

    Using the Controller With an Oil Bath Application Note #1 Using your 200-Series/Gemini controller with an oil bath is usually not recommended. J-KEM manufactures a 400-Series controller designed for use with oil bath and is recommended for this application. The 200-Series controller can be used safely with oil baths if the instructions in this application note are followed.

  • Page 30: Safety Considerations And Accurate Temperature Control

    Safety Considerations and Accurate Temperature Control For safety critical and non-typical organic reactions (especially polymeric reactions) or for use with heaters other than heating mantles the user must either 1) monitor the reaction closely to verify the tuning parameters are appropriate for the current application, or 2) autotune the controller for the application.

  • Page 31: Resetting The Controller To Original Factory Settings

    III. Resetting the Controller to Original Factory Settings J-KEM manufactures the most technically advanced temperature controller available and should give you consistently flawless control. If you have difficulty with your controller, a good place to start to correct the problem is by loading the original factory settings as detailed in the procedure below.

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