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J-KEM Scientific Gemini User Manual

Other manuals for Gemini: User Manual

Summary of Gemini

  • Page 1

    Temperature control for research and industry gemini user’s manual.

  • Page 2

    2.

  • Page 3: Warranty

    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 defect...

  • Page 4: Index

    Index section page 1. Quick operating instructions . . . . . . . . . . . . . . . . . . . . . . 4 kem-net data logging and control software . . . . . 5 2. Adjusting the controller for stable control with different heaters . . . . . . . . . . . . . . . . . . . . 6 2.1 what is tuning . . . . . . . . . ...

  • Page 5

    Section 1: quick operating instructions the four steps below are the basics of using your temperature controller. The user’s manual is a reference that explains the controller more fully as well as some of its more sophisticated features. It’s recommended that new users unfamiliar with process contr...

  • Page 6

    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 – the controller may ...

  • Page 7: Section 2:

    Section 2: 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 an...

  • Page 8

    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 ...

  • Page 9

    Os1 us os2 t1 t2 t3 t4 quarter cycle times temp new tuning values loaded into memory time start at set point 75% of set point during t1 - 4 the controller measures heating delays and rates of heating and cooling heat to set point after entering new parameters the autotune sequence. During autotune t...

  • Page 10

    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...

  • Page 11: Section 3:

    Section 3: operations guide 3.1 front panel description. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 (on back) figure 1 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...

  • Page 12

    10. 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. 11. Channel 1 power level selection. This button is the interface to j-kem’s patented power control computer ...

  • Page 13: Examples Of Program Ramps

    3.3 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 o c at a rate of 5 o c/hour), a second feature called ‘soak’ then lets you specify how long to stay at that temperature before turning o...

  • Page 14: Important Points To Know

    Important points to know 1. 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. 2. Channel 1 of this controller is equipped with a digital 100 hour timer, the digital timer a...

  • Page 15

    3.4 over temperature protection circuit. Note: the controller is shipped with the over temperature protection circuit disabled. To activate this circuit for either or both channels, follow procedure 3 below. Both channels of the gemini are equipped with over temperature protection circuits. This cir...

  • Page 16

    3.5 timer controls the 100 hour timer works with channel 1 only, it has no effect on channel 2. 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 incr...

  • Page 17

    Example power setting explanation 80 ml toluene 100 ml flask 100 ml heating mantle sp = 80o c 50 - 500 ml (25% power) organic solvents heated to 50 - 110 ≈ o c are set to the volume range on the front panel. When choosing between 2 power settings (i.E. 80 ml also falls within both the 10 - 100 ml ra...

  • Page 18

    3.8 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. 0 10 20 30 40 50 60 70 20 30 ...

  • Page 19

    0 10 20 30 40 50 60 70 20 45 70 95 120 145 170 temp c o time (min) conditions: 300 ml collidine 500 ml flask 500 ml heating mantle set point = 45 c power = 50 - 500 ml (25% power) o set point = 100 c power = 300 ml - 2 l (50% power) o set point = 155 c power = > 2 l (100% power) o graph 3 another fa...

  • Page 20: Procedure 4

    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 t...

  • Page 21

    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...

  • Page 22

    3.13 troubleshooting. Problem cause corrective action large over shoot of the set point (> 3o) during initial warm-up or unstable temperature control. Output power level is set too high. (make sure you’ve set the power level for the channel actually being used). Set the output power level to a lower...

  • Page 23

    Displayed temperature is incorrect. [note: types ‘k’ & ‘j’ the controller has not warmed-up. The display temperature reads low when the controller is first 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 of heati...

  • Page 24: Section 4:

    Section 4: application notes supplemental application notes on the following topics are available by contacting j-kem. Application note subject an1 how to heat oil baths with your controller. (included in appendix) an2 changing the controllers thermocouple type. An3 changing the heating outlet into ...

  • Page 25

    Imagine heating a gallon of water to 80 o 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. This delay might be a little annoying, but it's really no problem. The real problem comes a...

  • 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. 26.

  • Page 27

    After the controller is reprogrammed, place a fine gage wire thermocouple ( 1/3 the size of kite string; available from j-kem) in the bottom third of ≈ the heating mantle and fit the flask snugly on top so that the thermocouple is in intimate contact with the heating mantle. Set the output power lev...

  • Page 28

    Table 1 tuning parameters for various heaters fill in values determined for your equipment for quick reference. Instrument proportional band “band” integral time (reset) “int.T” derivative time (rate) “der.T” derivative approach cont. “dac” cycle time “cyc.T” heating mantles (factory default) 10 10 ...

  • Page 29: Appendix

    Appendix i. 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 ...

  • Page 30: II.

    Ii. 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 fo...

  • Page 31

    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 ...