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How to Set Up a Reaction with J-KEM Scientific’s 

Digital Temperature Controller 

 
 

This application note shows how to set up a typical heated reaction using J-KEM Scientific’s digital 
temperature controller.    For this example, the Model Gemini controller is used, but the application note 
applies equally well to all J-KEM temperature controller models.   If you have questions about specific 
models of temperature controllers, or any safety related question, please feel free to contact J-KEM 
Scientific.    This application note does not supercede any information in the Controllers actual User 
manual.   The User manual for each model is always the reference for that model. 
 
The Model Gemini is a dual channel controller that allows two independent reactions to be run on the same 
controller, one reaction on Channel 1 and the second on Channel 2.   In this example, we will only use 
channel 1. 
 
 

Thermocouple

Thermocouple extension
cord

Gemini Dual Channel
Temperature Controller

Channel 1 has a 100 hour
to turn heating On (Off)
at a user set time.

Channel 2 does
not have a timer

Thermocouple
receptacle

 

 

Summary of Contents for Gemini-230

Page 1: ...Temperature Control For Research and Industry Model Gemini 230 Manual For Serial Number...

Page 2: ...2...

Page 3: ...TICULAR PURPOSE IN NO EVENT SHALL J KEM SCIENTIFIC INC BE LIABLE FOR CONSEQUENTIAL INCIDENTAL OR SPECIAL DAMAGES THE BUYER S SOLE REMEDY FOR ANY BREACH OF THIS AGREEMENT BY J KEM SCIENTIFIC INC OR ANY...

Page 4: ...3 10 Resetting the Controller for use With Heating Mantles 23 3 11 Changing the Temperature Display Resolution 23 3 12 Changing Between PID and ON OFF Operating Modes 24 3 13 Troubleshooting 25 3 14...

Page 5: ...5...

Page 6: ...n steps 3 4 must be followed but also step 5 where the timer controls are set For more information on using the timer controls see Section 3 5 3 Set the power level switch to the volume of solution be...

Page 7: ...ways shows the effect that the timer controls have on the state of Channel 1 s output power When the controller is first turned on the timer window displays Off to indicate the timer controls have dis...

Page 8: ...nal Earth Ground General Notice WARNING If equipment is not used as specified in this manual the protection provided by this equipment may be impaired Stability The Gemini is equipped with a side moun...

Page 9: ...the controller from LabView or other software packages New Features GMP compliant data logging Exo and Enotherm monitoring KEM IO Remote Control of Laboratory Equipment based on Time and Temperature...

Page 10: ...to 0 1o C But to do this it must be programmed with the time constants describing how fast the heater heats and cools when electricity turns ON or OFF These time constants are called the tuning param...

Page 11: ...e equipment up in the exact configuration it will be used For example to tune to a vacuum oven place the thermocouple in the room temperature oven and plug the oven into the controller If the oven or...

Page 12: ...equipment to start at room temperature This procedure can be performed at any time and any temperature 2 Set the controller to the appropriate power level see Section 3 6 If tuning Channel 1 make sur...

Page 13: ...13 process temperature To abort autotune manually repeat steps 3 8 and 9 except in step 8 press the button until off is displayed...

Page 14: ...tuning parameters have been changed or the controller has been autotuned and you want to go back to using heating mantles J KEM recommends that the tuning parameters for heating mantles be loaded manu...

Page 15: ...ons 3 6 and 4 1 6 Timer Display Indicates the status of the timer See Section 3 5 for timer operation instructions 7 Timer Mode Selector Sets the operating mode of the timer See Section 3 5 for timer...

Page 16: ...16 have the same color plug as the input 9 on the controller...

Page 17: ...ture OFF the user must specifically turn Ramp to Setpoint ON When Ramp to Setpoint is OFF the controller heats to the entered setpoint at the fastest rate possible When Ramp to Setpoint is ON the cont...

Page 18: ...reaction temperature to increase temperature at the specified rate the heater must have sufficient power to heat at the entered rate This is a critically important point the user must understand that...

Page 19: ...and hold in both the and keys on the front of the temperature meter until the word tunE appears in the display then release both keys 4 Press the key 8 times until the word SPrr appears in the display...

Page 20: ...ey until SP2 A is showing in the display 5 Hold in the key while holding in the key press the key until nonE is showing in the display then let go of all the keys 6 Press the key until LEVL is showing...

Page 21: ...s three normal states of On toFF and t on If the Power Reduction Circuit Section 3 6 is set to the Heat Off position the timer window always displays oFF The four states of the timer circuit are expla...

Page 22: ...the timer rolls over from 00 to 59 minutes when entering minutes or from 00 to 99 hours when entering hours Push knob for 1 4 second Push knob for 1 4 second Push knob for 1 4 second Push knob for 1...

Page 23: ...of minutes rotate the timer knob to the left Rotate the knob to enter minutes Step 3 To change the number of hours in the display momentarily press the timer knob 1 4 second and the hours digits begi...

Page 24: ...en the timer starts the LED under the label ON at Zero lights This indicates that power to the heater will turn ON when the timer counts down to zero Hold in timer knob for 1 second to store time and...

Page 25: ...sk 1 L heating mantle SP 80o C 10 100 ml 10 power When the heating mantle size is substantially larger 5X than the volume being heated i e the heating mantle has excess heating capacity for the volume...

Page 26: ...demonstrating use of the output power level 0 10 20 30 40 50 60 70 20 30 40 50 60 70 80 Conditions Set point 75 C Laboratory oven o Power Setting 50 500 ml Power Setting 2L Conditions Set point 45 C H...

Page 27: ...power level to the Heat Off With the thermocouple or heater separated from the solution as the thermocouple cools the controller turns the heater on Since this heat is never fed back to the controller...

Page 28: ...while holding in the key press the or key until the value 3 0 appears in the display then let go of all the keys 6 Press the key once and the word CyC t will appear in the display First hold in the k...

Page 29: ...ined precisely The advantage of PID mode is that it delivers stable temperature control with any heater from heat lamps to vacuum ovens The disadvantage is that the controller must be properly tuned t...

Page 30: ...r The controller comes on but does not heat The timer controls are set incorrectly Change the position of switch 18 or enter a time into the timer See Section 3 5 The heater is broken To verify that t...

Page 31: ...ing the equation New Current Display display offset Displayed Correct Offset blinking in display temperature temperature 9 First hold in the key then while holding in the key press the or keys until t...

Page 32: ...closed loop feedback system If the process temperature is below the set point the controller turns the heating mantle on and then monitors the temperature rise of the solution If a small rise results...

Page 33: ...g the power off when the water temperature reached 60o C and allowing the latent heat of the burner to raise the water temperature from 60o to 80o C This calculation is done by the controller and is i...

Page 34: ...34 Procedure 4 in Section 3 10 will program the controller for heating mantles For all other heaters see tuning instructions in Section 2...

Page 35: ...the routine is started and cleared by turning the controller off This procedure must be started every time you want to record temperatures Procedure to Start Temperature Logging 1 Press and hold in b...

Page 36: ...ed question please feel free to contact J KEM Scientific This application note does not supercede any information in the Controllers actual User manual The User manual for each model is always the ref...

Page 37: ...coated Stainless steel no Teflon coating Teflon coated hypodermic needle Bend Temperature sensitive end of the thermocouple When a thermocouple is placed in solution often it is desirable to bend the...

Page 38: ...h any 230 Vac heating mantle 100ml and larger They are not compatible with any size oil bath Shown is a typical set up for a solution phase reaction 1 Place the reaction flask in the appropriate size...

Page 39: ...ntrol Computer PCC that precisely regulates power to the heater For the computer to work correctly it must know the volume of solution that is being heated It s important to understand that the PCC is...

Page 40: ...ases the controller may need to be autotuned for the oil bath see User s Manual but this is discouraged unless you ll be using the oil bath frequently 2 If the reason for using an oil bath is that a s...

Page 41: ...mpared to water since the coefficient of heat for hexane is 0 54 calories g o C and water is 1 0 calorie gram o C That means that 1000 watt seconds of input power will raise the temperature of 10 g of...

Page 42: ...eduction circuit is set to the proper setting of 10 100 ml which limits the heating mantles output power to about 5 watts the correct amount of power needed in this application Consideration 2 The PID...

Page 43: ...etpoint was changed to 250 C As you can see the heating mantle doesn t have enough power at the 10 100 ml setting to heat the reaction to 250 C and so it stalls out at about 150 C The solution is to i...

Page 44: ...again results in stable temperature control J KEM does not recommend autotuning the controller every time a unique heating application is needed because in the example above now that the controller i...

Page 45: ...ress the key once and the word SP1 d appears in the display Next hold in the key then while holding in the key press the key until the value SSd appears in the display Let go of all the keys 7 Press t...

Page 46: ...Let go of all the keys If the TOP meter is being reset enter the value ___________ If the BOTTOM meter is being reset enter the value ___________ 25 Press the key until the word LEVL appears in the di...

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