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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: Warranty

    2 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 defe...

  • Page 3: Index

    3 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 4

    4 section 1: quick operating instructions the five steps below are the basics of using your temperature controller. It’s recommended that new users unfamiliar with process controllers read the entire manual carefully. The controller is preprogrammed for use with heating mantles fitted to round botto...

  • Page 5

    5 kem-net data logging and control software in 2008, j-kem completed a redesign of it’s research grade controllers. The redesign involved both the hardware running your controller and software for remote control and data logging. Hardware – the controller may look the same, but inside is our 3 rd ge...

  • Page 6: Section 2:

    6 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 ...

  • Page 7

    7 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 controlle...

  • Page 8

    8 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...

  • Page 9

    9 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...

  • Page 10: Section 3:

    10 section 3: operations guide 3.1 front panel description. The gemini controller has two independent temperature controllers in a single cabinet. The two controllers are labeled channel 1 and channel 2. The controls for channel 1 have no affect on the operation of channel 2 and visa versa. Controls...

  • Page 11: Examples of Program Ramps

    11 3.2 heater restrictions. Each channel of the controller can individually deliver up to 10 amps of current at 120 vac, but the combined total current from channels 1 & 2 can not exceed 15 amps. These current ratings are limited to resistive loads (heating mantles, hot plates, ovens, etc.). Use onl...

  • Page 12: Important Points to Know

    12 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 ti...

  • Page 13

    13 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...

  • Page 14

    14 3.5 timer controls the 100 hour timer works with channel 1 only, it has no effect on channel 2. The timer circuit works in conjunction with the digital meter to determine when power is applied to the heater. The digital meter is the actual temperature controller, the timer circuit only acts as a ...

  • Page 15

    15 over view of the timer functions the timer knob is a multi-function knob. When it’s pushed in for 1/4 second it causes the timer to advance to the next function. When it’s pushed in for 1 second it enters programming mode. In programming mode, the user enters time into the timer or locks the ente...

  • Page 16

    16 heating for a set period of time in this mode, the user enters the amount of time to heat before turning heating off permanently. This is useful to heat a reaction or other lab instrument for a set period of time and then have the reaction stop heating automatically. While at this setting and whi...

  • Page 17

    17 delay heating for a set period of time in this mode, the user enters an amount of time to delay before turning on power to the heater. This is useful to start heating a reaction or piece of equipment automatically at a specific time. While at this setting and while entering a time into the timer,...

  • Page 18

    18 heating liquids. Each power level is associated with a volume range which acts as a guide when heating solutions with heating mantles. When solutions are heated with heating mantles set the power switch to the range that includes the volume of solution being heated [note: this switch is set to th...

  • Page 19

    19 3.7 temperature sensor input. Both channels of the controller are fitted with a specific type of thermocouple input and can only be used with a thermocouple of the same type. For the correct temperature to be displayed, the thermocouple type must match the receptacle type on the front of the cont...

  • Page 20

    20 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...

  • Page 21: Procedure 4

    21 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 followin...

  • Page 22

    22 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...

  • Page 23

    23 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 lo...

  • Page 24

    24 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 he...

  • Page 25: Section 4:

    25 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 in...

  • Page 26

    26 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...

  • Page 27

    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 ...

  • Page 28: Appendix

    28 appendix i. Using the controller with an oil bath application note #1 using your 200-series controller with oil baths rated for less than 120 volt operation is not recommended. J-kem manufactures a 400-series controller designed for use with oil baths rated for any voltage and is recommended for ...

  • Page 29

    29 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...

  • Page 30

    30 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 t...

  • Page 31

    31 15. Press the ▼ key until the word “levl” appears in the display. 16. First hold in the ‘*’ key, then while holding in the ‘*’ key press the ▲ key until “2” appears in the display. Let go of all the keys. 17. Press the ▲ key until “sp2.A” appears in the display. Next, hold in the ‘*’ key, then wh...