J-KEM Scientific Gemini User manual

Temperature Control For Research and Industry
Gemini
User’s Manual

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 defective upon examination by
J-KEM, it will be repaired or replaced at no charge. However, this WARRANTY is VOID if the unit
shows evidence of having been tampered with or shows evidence of being damaged as a result of
excessive current, heat, moisture, vibration, corrosive materials, or misuse. This WARRANTY is
VOID if devices other than those specified in Section 3.2 are powered by the controller. Components
which wear or are damaged by misuse are not warranted. This includes contact points, fuses and solid
state relays.
THERE ARE NO WARRANTIES EXCEPT AS STATED HEREIN. THERE ARE NO OTHER
WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND OF FITNESS FOR A PARTICULAR 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 BREACH OF ANY WARRANTY
BY J-KEM SCIENTIFIC, INC. SHALL NOT EXCEED THE PURCHASE PRICE PAID BY THE
PURCHASER TO J-KEM SCIENTIFIC, INC. FOR THE UNIT OR UNITS OF EQUIPMENT
DIRECTLY AFFECTED BY SUCH BREACH.
Service
J-KEM Scientific maintains its own service facility and technical staff to service all parts of the controller,
usually in 24 hours. For service, contact:
J-KEM Scientific, Inc.
6970 Olive Boulevard
St. Louis, MO 63130
USA
[phone]
fax [phone]
E-Mail: [email protected]
Internet on-line catalog: www:jkem.com
This manual contains parameters specific to temperature controller Serial #_________________.
When calling with a technical question, please have the controller’s serial number available.
You’ve purchased the most versatile controller available to the research community. We’re
confident it can regulate ANY heating/cooling situation you’ll ever encounter. If the information in this
manual isn’t adequate for your application, contact our Engineering Department for assistance.
– With J-KEM’s patented Microtune circuitry –
3

INDEX
SECTION PAGE
1. QUICK OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . 4
KEM-NET DATA LOGGING AND CONTROL OFTWARE . . . . . 5
2. ADJUSTING THE CONTROLLER FOR STABLE
CONTROL WITH DIFFERENT HEATERS . . . . . . . . . . . . . . . . . . . . 6
2.1 What is Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Autotuning Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Tuning for Heating Mantles: A Special Case . . . . . . . . . . . . . . . . 9
2.4 Sensor Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3. OPERATIONS GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 Front Panel Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2 Heater Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3 Ramp-to-Setpoint & Soak Feature . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.4 Over Temperature Protection Circuit . . . . . . . . . . . . . . . . . . . . . . . 14
3.5 Timer Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.6 Output Power Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.7 Temperature Sensor Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.8 Affect of Power Setting on Heating Profile . . . . . . . . . . . . . . . . . . 17
3.9 Do's and Don'ts When Using Your Controller . . . . . . . . . . . . . . . . 18
3.10 Resetting the Controller for use With Heating Mantles . . . . . . . . . 19
3.11 Changing the Temperature Display Resolution . . . . . . . . . . . . . . . . 19
3.12 Changing Between PID and ON/OFF Operating Modes . . . . . . . . 20
3.13 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4. APPLICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.1 Theory of How the Controller Works – Simply . . . . . . . . . . . . . . 23
4.2 Controlling a Heating Mantle Temperature Directly . . . . . . . . . . . 24
4.3 Automatic Storage of Min/Max Temperatures . . . . . . . . . . . . . . . . 25
TABLE 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
I. Using the Controller With an Oil Bath (Application Note 1) . . . . . 27
II. Safety Considerations and Accurate Temperature Control . . . . . . . 28
III. Resetting the Controller to Original Factory Settings . . . . . . . . . . . 29
WARNING: Adhere to the restrictions of SECTION 3.2. Failure to do so may create a
significant safety hazard and will void the warranty.
4

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 controllers read the entire manual carefully. The controller is preprogrammed for use with heating mantles fitted
to round bottomed flasks running “typical” organic reactions (i.e., non-polymeric reactions in solvents such as THF,
toluene, DMF, etc.). If the controller is used with this type of reaction, the 3 steps below will help you get started.
To use heaters other than heating mantles: See Section 2.
Do not use the controller to heat oil baths: See Section 3.2 & Appendix I.
For polymer synthesis, atypical, expensive, or safety critical reactions: 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.
1Place the thermocouple in the solution being heated. Place at least the first 1/4” of the
thermocouple directly in the solution being heated. Thermocouples can be bent without harming them. If you’re
heating a corrosive liquid, use a Teflon coated thermocouple. If you are heating a sealed reaction, see Section 4.2.
2Set the power level
switch to the volume of
solution being heated (not
the size of the flask being used).
Adjust the power
Output Power Level
1 -
10 ml
10 -
100 ml
50 -
500 ml
300 ml
- 2 L
>2 L
Heat
Off
Channel 1
Channel 2
TIP: Because the
power switch acts like
a variac, if the reaction
is heating too slowly
or you need more
power
level for the channel being used.
The power level switch can be
thought of as a solid state variac.
Volume ranges are printed above
this switch as a guide to select the
correct power level since it’s easier
to guess the volume being heated
than the appropriate “percent
power” to apply to a heater. ‘Heat
Off’ turns off the heater so the
controller displays temperature
only. Section 3.6 should be read by
all new users.
A power is equivalent to
setting of..... a variac setting of:
1 10 ml 3%
10 100 ml 10%
50 500 ml 25%
300 ml 2 L 50%
> 2 L 100%
(e.g., heating to high temperatures), give
the heater more power by turning the
power level up one setting. If the
reaction needs less power than
normal(e.g., heating to low temperatures
(<60o C) or the temperature overshoots
the set point excessively, turn the power
down one setting. DO NOT set the
power switch on a setting too high
initially to heat the reaction quickly and
then lower it to the correct setting, this
degrades heating performance.
3Enter the setpoint (i.e., the desired temperature). Hold in
the ❊button and simultaneously press the key to increase or the▲ ▼
key to decrease the setpoint. The setpoint can be seen at anytime by
holding in the ❊button, the setpoint appears as a blinking number in
the display.
4Set the timer.
The timer turns the heating
outlet OFF or ON depending
on the position of the timer
switch and whether any time is
present in the display
5

KEM-Net Data Logging and Control oftware
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 look the same, but inside is our 3rd generation microcontroller. This
controller is FLASH programmable and capable of downloading program modules(software) from
our web site at no charge. Several program modules are in development, but the most exciting is a
module that automatically reports exothermic reactions – even during the heating phase of a reaction
when an exotherm would normally be undetectable.
Software - Your controller is equipped with a USB port to allow remote control and data logging.
J-KEM is currently developing a complementary software package, KEM-Net, that remotely
controls and data logs up to 16 controllers simultaneously. Until KEM-Net is available, J-KEM is
offering KEM-Log at no charge.
KEM-Log provides remote
control and data logging for
one J-KEM controller.
KEM-Log implements:
* Data logging directly
to Excel or a text file.
* A 16-step
temperature ramp
that’s constructed in
an Excel-like table.
* Easy entry of the
setpoint
KEM-Log is free of charge. To load KEM-Log to your PC, follow these steps:
1. Enter this link in your web browser: http://www.jkem.com/kemnetzip.exe
A popup window appears presenting the options of RUN, SAVE and CANCEL. Selecting the
SAVE option brings up a Save File Dialog window. Save the file kemnetzip.exe to your C
drive, then exit your web browser.
2. Kemnetzip.exe is a self-extracting zip file. Double click on its icon to expand it. Once
expanded, kemnetzip.exe creates a new folder on your C drive titled "JKEM" which contains
the KEM-Net Installation Project and copies of user's manuals and USB drivers.
3. Print the document titled PrintMe_Now.pdf for instruction on how to install the USB drivers
and the KEM-Net software.
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 and adjusted separately.
2.1 What is Tuning. The controller's most powerful feature is its ability to regulate virtually any heater
with stable temperature control. To achieve stable control, the controller must 1) be set to the correct
power level (see Section 3.6) and, 2) be tuned to the heater being used. Tuning is the process that matches
the control characteristics of the controller to the heating characteristics of the heater. The controller is
said to be tuned to the heater when its memory is programmed with values describing how fast the heater
warms up, cools off, and how efficiently it transfers heat. For example, consider the difference between a
heat lamp and a hot plate. When electricity is applied to a heat lamp it begins to heat instantaneously, and
when it's turned off it stops heating instantaneously. In contrast, a hot plate takes several minutes to begin
heating when electricity is applied and even longer to stop heating when electricity is turned off. Your
controller can regulate both a heat lamp and a hot plate to 0.1oC. 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 parameters.
Every type of heater has its own unique set of tuning parameters. For the controller to heat with
stability, it must have programmed with the tuning parameters for the heater currently being used. Prior to
shipment, tuning parameters were programmed into the controller that maximize heating performance for
laboratory heating mantles since these are the most common heaters used in research. Tuning is regulated
by 5 of the temperature meter’s user programmable functions. The correct value for these 5 functions can
be calculated and loaded manually, or the controller can do it automatically with its autotune feature.
When Should the Controller be Tuned? If the controller is tuned to one type of heater, heating
mantles for example, any size heating mantle can be used without the need to retune. When changing
from heating mantles to a different type of heater, an oven for example, the controller should be tuned
with values describing the oven’s heating characteristics. The effect of tuning is seen below. When
the controller is tuned for heating mantles, using it with any size heating mantle yields stable
temperature control (Plot 1), but poor control results when the same tuning parameters are used with
an oven (Plot 2, Curve 1). However, after tuning the controller to the oven, stable temperature control
results (Plot 2, Curve 2).
20
30
40
50
60
70
80
0 10 20 30 40 50 60
Time (min)
Temp.
o
C100 ml Toluene
250 ml Round bottomed flask
250 ml Heating mantle
Power Setting = 50 500 ml
Conditions:
Plot 1
20
30
40
50
60
70
80
0 10 20 30 40 50 60
Controller loaded with
tuning parameters for
heating mantles
Controller loaded with
tuning parameters for
drying oven
Curve 2:
Curve 1:
Time (min)
Temp.
o
C
Plot 2
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 controller predicts (calculates)
the percent of power to apply to the heater now to control the shape of the heating curve minutes in
advance. The importance of the tuning parameters is that they are constants in the equation the
temperature meter uses to perform its predictive calculations. If the temperature meter is programmed
with tuning parameters that incorrectly describe the heater being used, poor temperature control will result.
But, when the correct values are loaded, temperature regulation of ± 0.1ois typically achieved.
Manual Tuning. Manual tuning is when the values of the 5 tuning parameters are determined
manually then entered into the temperature meter via the push buttons on the front of the controller.
Experienced users might prefer to manually tune the controller since this allows customization of the
heating process.
Autotune. Autotune is a feature built into the temperature meter that automatically calculates the
tuning parameters (i.e. delay times, heating efficiency, etc.) for any type of heater. After the autotune
procedure is complete and the tuning parameters are determined, the controller loads them into its
memory for current and future use. Heating mantles are a special case and are covered in a separate
paragraph (Section 2.3).
2.2 Autotuning Procedure.
This procedure is not recommended for heating mantles (see Section 2.3). Perform this
procedure only on the controller channel in use.
1. Set the 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 heater) has its own thermostat or power control, turn both as high as
they’ll go.
2. Set the controller to the appropriate power level (see Section 3.6). If tuning Channel 1, make
sure the timer switch is set so that heating is on (i.e., LED 17 is lit; see Section 3.5). Turn the
controller and heater on, then enter the desired set point temperature. If the set point isn’t at
least 30oC above ambient, skip this procedure and go to the next procedure, “Autotuning the
Controller for Very Fine Control”
3. Press and hold in both the and buttons (for 3 seconds) on the front of the temperature▲ ▼
meter until the word “tunE” appears in the display then release both buttons.
4. Press the button (5 times) until “▲CyC.t” appears in the display (if you go past this setting,
press the button until you get back to it).▼
5. First, hold in the ‘*’ button, while holding in the ‘*’ button press the button. Continue to▼
hold both buttons in until the display reads “A --”, or “A ##” where “##” is some number.
6. Release the ‘*’ button and press the button until “▼tunE” once again appears in the display.
7. Press and hold the ‘*’ button and “tunE” will change to “off” to indicate that autotune is
currently off.
8. While holding in the ‘*’ button, press the button to change the display to “▲on”, then release
both buttons.
9. Press and hold both the and buttons (for 3 seconds) until the temperature appears in the▲ ▼
display. The controller is now in its autotune mode. While in autotune the display alternates
between “tunE” (for autotune) and the process temperature. When the autotune sequence is
done (this may take in excess of an hour) the controller stops displaying “tunE” and only
displays the process temperature. [To abort autotune manually, repeat steps 3, 8 and 9 except in
step 8 press the button until “▼off” is displayed].
8

OS1
US
OS2
T1 T2 T3 T4
Quarter cycle times
Temp New tu i g
values loaded
i to memory
Time
Start
AT
Set
Poi t
75% of
set poi t
Duri g T1 - 4 the co troller
measures heati g delays a d
rates of heati g a d cooli g
Heat to set poi t
after e teri g
ew parameters
The autotune sequence.
During autotune the controller heats
to 75% of the set point temperature
where it oscillates for several cycles
before loading the new tuning
parameters. After the tuning
parameters are loaded it heats to the
set point temperature. Tuning below
the set point prevents any damage that
might occur from overheating.
Autotuning the Controller for Very Fine Control.
This procedure is not recommended for heating mantles (see Section 2.3).
In the majority of cases, the procedure above results in stable temperature control with any heater. A
second version of the autotune routine is available and can be used when the heater is already at or
close to the set point, is being tuned at a temperature close to room temperature, or for very fine
control in demanding situations. If stable temperature control doesn’t result after performing the first
autotune routine, the procedure below should be performed. Before performing the ‘fine tune’
autotune procedure, the ‘regular’ autotune procedure that precedes this should normally be performed.
1. Set the equipment up in the exact configuration it will be used. If the heater has its own
thermostat or power controls, turn both as high as they’ll go. With this procedure it’s not
necessary for the 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
sure the timer switch is set so that heating is on (i.e., LED 17 is lit; see Section 3.5). Turn the
controller and heater on, then enter the desired set point temperature.
3. Press and hold in both the and buttons (for 3 seconds) on the front of the temperature▲ ▼
meter until the word “tunE” appears in the display then release both buttons.
4. Press the button (5 times) until “▲CyC.t” appears in the display (if you go past this setting,
press the button until you get back to it).▼
5. First hold in the ‘*’ button, while holding in the ‘*’ button press the button. Continue to▼
hold both buttons in until the display reads “A --”, or “A ##” where “##” is some number.
6. Release the ‘*’ button and press the button until “▼tunE” once again appears in the display.
7. Press and hold the ‘*’ button and “tunE” will change to “off” to indicate that autotune is
currently off.
8. While holding in the ‘*’ button, press the button to change the display to “▲At.SP”, then
release both buttons.
9. Press and hold both the and buttons ( 3 seconds) until the temperature appears in the≈▲ ▼
display. The controller is now in its autotune mode. While in autotune the display alternates
between “tunE” (for autotune) and the process temperature. When the autotune sequence is
done (this may take in excess of an hour) the controller stops displaying “tunE” and only
displays the process temperature. [To abort autotune manually, repeat steps 3, 8 and 9 except in
step 8 press the button until “▼off” is displayed].
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 fails
again, call and discuss your application with one of our engineers. A common problem when tuning
at high temperatures or with large volumes is for the heater to be underpowered. A more powerful
heater may be needed (contact J-KEM for assistance).
2.3 Tuning for Heating Mantles: A Special Case. This section gives special consideration to heating
mantles, since they’re the most commonly used heaters in research. Every heating mantle size has its own
optimum set of tuning parameters and if you wanted, the controller could be tuned (or autotuned) every
time a different size was used. However, this is cumbersome and is also unnecessary. Factory tests show
that there’s one set of tuning parameters that delivers good performance for all heating mantle sizes. These
tuning parameters were loaded into the controller at the factory prior to your receiving it. If you’re using a
heating mantle and none of the parameters have been changed or the controller hasn’t been autotuned since
you’ve received it, you’re ready to go. If the 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 manually (i.e., don’t autotune to the heating mantle) by following
the step-by-step instructions given in Procedure 4 of Section 3.10.
2.4 Sensor Placement. Placement of the sensor is basically common sense. The sensor should be
positioned to sense the average temperature of the medium being heated. That means the thermocouple
should be shielded from direct exposure to the heater but not so distant that a rise in temperature isn’t
sensed by the controller within a reasonable period of time. Several examples follow that show the type
of consideration that should be given to sensor placement.
Use With:
Solutions Place the sensor in the solution. Stir vigorously so that heat is homogeneously mixed throughout the solution.
HPLC column heated
with a heating tape
Tape a thin wire thermocouple directly to the HPLC column. Place several layers of
paper over the thermocouple to insulate it from the heating tape (the thermocouple
should sense the column temperature, not the heater temperature). Wrap the HPLC
column completely with heating tape.
Oven The thermocouple needs to be shielded from transient hot and cold air currents. Don’t place the thermocouple near the heating coil or an air vent. A small thermocouple
(1/16” or 1/8” thermocouple) that responds rapidly to changes in air temperature is better
than a larger one.
10

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 ‘*’ button is held in.
2. Channel 2 Temperature Display. Shows temperature of the process connected to Channel 2 as the
default display. Shows set point temperature (i.e. desired temperature) when ‘*’ button is held in.
3. Control Key (shown for Channel 2, but the same is true for Channel 1). When pressed, the display
shows the set point temperature. To decrease or increase the set point, press the ‘▼’ key (4) or ‘▲’ key
(5), while simultaneously pressing the control key. The set point appears as a blinking number in
the display.
4. Down Key (shown for Channel 2, but the same is true for Channel 1). Lowers set point when ‘*’
button (3) is simultaneously pressed.
5. Up Key (shown for Channel 2, but the same is true for Channel 1) Raises set point when ‘*’ button
(3) is simultaneously pressed.
6. Channel 1 On/Off Switch. For maximum display accuracy, turn on the controller 30 minutes prior
to use. WARNING: Due to the nature of solid state relays, a small amount of output power (7.5
mA @ 120 VAC; 0.9 watts) is present at outlet (9) even when the controller is turned off. Take
appropriate precautions to avoid electrical shock.
7. Channel 2 On/Off Switch. For maximum display accuracy, turn on the controller 30 minutes prior
to use. WARNING: Due to the nature of solid state relays, a small amount of output power (7.5
mA @ 120 VAC; 0.9 watts) is present at outlet (13) even when the controller is turned off. Take
appropriate precautions to avoid electrical shock.
8. Channel 1 Temperature Sensor Input. Use the same type of sensor probe as the sensor plug installed
on the controller (see Section 3.7). The correct sensor type will have the same color plug as the
input (8) on the front of the controller.
9. Channel 1 Power Outlet. Plug only 120 VAC devices into this outlet (see Section 3.2).
11

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 which limits the maximum power delivered to the heater. See Sections 3.6 and 4.1.
12. Channel 2 Temperature Sensor Input. Use the same type of sensor probe as the sensor plug installed
on the controller (see Section 3.7). The correct sensor type will have the same color plug as the
input (12) on the front of the controller.
13. Channel 2 Power Outlet. Plug only 120 VAC devices into this outlet (see Section 3.2).
14. Indicates the present power level of Channel 1 (see Section 3.6).
15. Indicates the present power level of Channel 2 (see Section 3.6).
16. Displays the time remaining in the 100 Hr. timer for Channel 1.
17. Indicates whether the timer has turned power ON or OFF at Channel 1's outlet. This LED is lit
when the timer section has turned power ON at outlet (9) and off when the timer has turned power
OFF at outlet (9).
18. This switch, in conjunction with the timer, determines when power is present at outlet (9). See
Section 3.5. The label ‘When time = 0 turn outlet:’ has reference to the time remaining in display
(16).
19. Increases or decreases the time remaining in the timer when pressed.
20. Optional 9-pin serial connector. For controllers equipped for serial communications, this RS232
port connects to a PC for remote control and data acquisition. For units set up for multi-controller
operation a RJ-11 phone connector may also be on the back of the controller.
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 only resistive loads
that are safely operated at 120 VAC and require less than 10 amps or damage to the controller and a
safety hazard may result.
•Do not plug oil baths into your controller. Oil baths are not 120 VAC devices and
become a fire hazard unless properly connected to the controller. (See Appendix for
an application note describing the use of oil baths with this controller). Ask about J-
KEM’s new 400 series controllers for use with oil baths.
• Devices other than resistive loads can be used with your controller but certain restrictions
apply.
Device Type Restrictions Comments
Incandescent lamps
Infrared heaters 700 watts≤Set the output power level to the > 2 L setting.
Inductive loads:
* solenoids
* transformers
* motors
4 amps; 480 watts≤The controller must be
programmed for this use.
Request application note AN5.
12

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 120oC at a rate of 5oC/Hour), a second
feature called ‘Soak’ then lets you specify how long to stay at that temperature before turning off.
Examples of Program Ramps
.
Setpoint
Temperature
Time
Ramp
Soak
Power Off
Setpoint
Temperature
Time
Ramp
Soak
Power Off
The controller is shipped with the Ramp-to-Setpoint feature 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 controller heats at the user entered ramp rate.
The Ramp-to-Setpoint feature and its associated parameters are turned on and set in the controller’s
programming mode. The parameters of importance are:
SPrr SetPoint Ramp Rate. Allowable Values: 0 to 9990 deg/Hr.
This specifies the desired rate of heating (cooling). Note, this parameter specifies the desired rate of
heating (cooling), but in cases of extremely high ramp rates the reaction will not actually heat faster than
the power of the heater will allow.
SPrn SetPoint Ramp Run. Allowable Values: ON, OFF, Hold
This parameter turns the Ramp-to-Setpoint feature ON or OFF. During an active run, if this parameter is
set to ‘Hold’, the setpoint ramp stops and holds at its’ current value. This continues until the parameter is
set to ON or OFF. When set to OFF, the values in SetPoint Ramp Rate and Soak Time are ignored.
SoAK Soak Time. Allowable Values: “- -”, 0 to 1440 min.
This specifies the amount of time to soak at the setpoint after the setpoint temperature ramp is complete.
A setting of “- -” causes the controller to remain at the final setpoint indefinitely. A numeric value causes
the controller to stay at the setpoint for the entered time and then turn power to the heater off after the time
expires.
13

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 and the Ramp-
to-Setpoint feature are completely independent of each other. For example, if the digital timer is set
to turn heating OFF after 5 hours, heating is turned off even if a ramp step is in progress. Likewise,
if a Soak time turns heating off after 3 hours and the digital timer is set to turn heating off after 10
hours, the digital timer has no effect since the expired Soak time already has turned heating off. To
avoid confusion and conflicts between the meters “Hold” feature and the front panel digital timer, it’s
recommended that the Soak Time feature of Channel 1 be set to “––” in the meters setup menu and
not changed.
For Channel 2 Only: It may be useful to use the “Hold” feature on Channel 2 to automatically turn
power off to the heater after a specified period of time since Channel 2 does not have a front panel
digital timer.
3. Setting a ramp rate doesn’t guarantee that the reaction temperature is at the specified ramp
temperature since heating is dependent on the power of the heater. For example, if a ramp rate of
1200 deg/Hr (i.e., 20 deg/min) is set, unless the heater is powerful enough to impart heat at such a
high rate, the reaction temperature will not track the ramp temperature. Likewise, a reaction can’t
cool faster than natural cooling by ambient air.
4. Once the Ramp-to-Setpoint feature is activated in programming mode, it remains on until it’s
deactivated in programming mode. The Ramp-to-Setpoint feature remains activated even if power is
turned off to the controller.
Activating & Programming the Ramp-to-Setpoint Feature
1. Press 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.
2. Press the key (8 times) until the word “▲SPrr” appears in the display.
This is were you set the ramp rate in units of degrees/hour. First hold in the ‘*’ key, then while holding in the ‘*’ key
press the or key until the desired ramp rate appears in the display, then let go of all the keys. Units are in▼ ▲
degrees/hour.
3. Press the key once and the word “▲SPrn” will appear in the display.
This function turns the ramping feature ON, OFF, or to Hold. First hold in the ‘*’ key, then while holding in the ‘*’
key press the or key until the desired setting appears in the display, then let go of all the keys.▼ ▲
4. Press the key once and the word “▲SoaK” will appear in the display.
This is where the soak time is set in units of Minutes. A soak time of ‘ -- ‘ means to ‘soak forever’ (this setting is one
below ‘0’). First hold in the ‘*’ key, then while holding in the ‘*’ key press the or key until the desired time▼ ▲
appears in the display, then let go of all the keys. If a soak time is set, the controller display will alternate between
showing the current reaction temperature and the word “StoP” when the soak time has expired to indicate that power
has been turned off.
5. To exit programming mode, press and hold in both the and keys until the temperature appears in the display, then▼ ▲
release both keys.
Deactivating the Ramp-to-Setpoint Feature
1. Press 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.
2. Press the key (9 times) until the word “▲SPrn” appears in the display.
This function turns the ramping feature ON and OFF. First hold in the ‘*’ key, then while holding in the ‘*’ key press
the or key until OFF appears in the display, then let go of all the keys.▼ ▲
3. To exit programming mode, press and hold in both the and keys until the temperature appears in the display, then▼ ▲
release both keys.
14

3.4 Over Temperature Protection Circuit.
NOTE: The controller is shipped with the Over
Temperature Protection Circuit DI ABLED. 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 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. Power remains disconnected until the Output Power Level button for that
channel is pressed. If the circuit for Channel 1 is triggered the timer window displays the message
“HELP” and the power level LED for that channel blinks. If the circuit for Channel 2 is triggered, the
power level LED for Channel 2 blinks but the display does not show the word “HELP”. The high
temperature limit (i.e. the limit that must be exceeded to trigger this circuit) is factory set to 5 degrees for
both channels, but can be changed or enabled or disabled as outlined in the procedures below. The over
temperature protection circuit for Channels 1 & 2 are independent of each other. A temperature limit
entered into the temperature meter controlling Channel 1 has no affect on Channel 2 and visa versa.
To reset a sounding alarm: 1) Correct the condition causing the alarm. 2) Press the Output Power
Level button (once) for the channel who’s power level LED is blinking.
Procedure 1. To Change the Number of Degrees that the Reaction Temperature Must Exceed the Set Point to Trigger the Over Temperature Alarm, Perform this Procedure.
Press and hold in both the and keys on the front of the temperature meter for the Channel you want to change until the word▼ ▲
“tunE” appears in the display, then release both keys.
Press the key until “▲SEt.2” is showing in the display.
First hold in the ‘*’ key, while holding in the ‘*’ key press the or keys until the temperature limit you want is showing in the▼ ▲
display, then let go of all the keys.
Press and hold in both the and keys until the temperature is showing again.▼ ▲
Procedure 2. To Permanently Disable the Over Temperature Circuit, Perform this Procedure.
Press and hold in both the and keys on the front of the temperature meter for the Channel you want to change until the word▼ ▲
“tunE” appears in the display, then release both keys.
Press the key until “▼LEVL” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▲2” is showing in the display, then let go of all the keys.
Press the key until “▲SP2.A” is showing in the display.
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.
Press the key until “▼LEVL” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▲3” is showing in the display, then let go of all the keys.
Press the key until “▲rEU.d” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▼1r.2d” is showing in the display, then let go of all the keys.
Press and hold in both the and keys until the temperature is showing again. When you do this, the alarm will sound.▼ ▲
Increase the set point by any amount by first hold in the ‘*’ key, then while holding in the ‘*’ key press the key.▲
Reset the alarm by pressing the Output Power Level button once for the channel you’re changing. This completes this change.
Procedure 3. To Enable the Over Temperature Protection Circuit, Perform this Procedure.
Press and hold in both the and keys on the front of the temperature meter for the Channel you want to change until the word▼ ▲
“tunE” appears in the display, then release both keys.
Press the key until “▼LEVL” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▲2” is showing in the display, then let go of all the keys.
Press the key until “▲SP2.A” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▲dU.hi” is showing in the display, then let go of all the keys.
Press the key until “▼LEVL” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▲3” is showing in the display, then let go of all the keys.
Press the key until “▲rEU.d” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▲1r.2r” is showing in the display, then let go of all the keys.
Press the key until “▼LEVL” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▼1” is showing in the display, then let go of all the keys.
Press the key until “▲SEt.2” is showing in the display.
Hold in the ‘*’ key, while holding in the ‘*’ key press the key until “▲5.0” is showing in the display, then let go of all the keys.
Press and hold in both the and keys until the temperature is showing again.▼ ▲
15

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 increase
or decrease the displayed time. The format of the display is ‘Hr : Min’.
A simple way to know whether outlet 9 is on or off is by the state of LED 17 which is lit when the outlet is
on and not lit when it’s off.
Outlet 9 will be ON or OFF depending on the position of switch 18 as outlined in the table below.
Switch 18 Time Remaining Outlet 9 LED 17
Position in Timer is: is Comment
[When time = 0
turn outlet:] Zero OFF OFF
OFF >Zero ON ON Outlet 9 will remain ON until the
timer counts down to zero, at which
point the outlet will turn OFF and
stay off indefinitely.
[When time = 0
turn outlet:] Zero ON ON
ON > Zero OFF OFF Outlet 9 will remain OFF until the
timer counts down to zero, at which
point the outlet will turn ON and
stay on indefinitely.
3.6 Output Power Level This circuit (Figure 1, #’s 10 & 11) is the user’s interface to J-KEM’s patented
power control computer which limits the maximum output power delivered by the controller. It
determines whether the controller heats at a very low (1-10 mL), low (10 - 100 mL), intermediate (50 - 500
mL), medium (300 mL - 2 L), or high (>2 L) power level. The power level set for Channels 1 & 2 are
independent of one another.
The output power circuit acts as a solid state variac. This circuit has an additional setting: “Heat Off”
which, when selected, turns heating off and allows the controller to act as a digital thermometer. The
table to the right shows the maximum output power from the controller to the heater depending on the
position of the power switch. The correct setting for this switch is the setting that supplies adequate
power for the heater to heat to the set point in a reasonable period of time while at the same time not
overpowering it.
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 the volume of solution, not the size of the
flask]. For example to heat 250 ml of toluene to 80oC in a
1 L round bottomed
Front Panel Approx. % of
Volume Range Full Power
1 - 10 mL 3
10 - 100 mL 10
50 - 500 mL 25
300 ml - 2 L 50
2 L≥100
flask choose the third power setting (50 - 500 ml) since the solution volume falls within this range. There
are situations when a power level other than that indicated on the front panel should be used:
16

Example Power Setting Explanation
80 ml toluene
100 ml flask
100 ml heating mantle
SP = 80oC
50 - 500 ml
(25% power) Organic solvents heated to 50 - 110≈oC 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 range
and the 50 - 500 ml range) choose the higher setting.
80 ml collidine
100 ml flask
100 ml heating mantle
SP = 170oC
300 ml - 2 L
(50% power)
Even though the solvent volume is less than the range of this
power setting, it should be used because high temperatures
require additional power.
80 ml water
100 ml flask
100 ml heating mantle
SP = 80oC
300 ml - 2 L
(50% power)
While the setting 50 - 500 ml would work, since the heat
capacity of water is twice that of a typical organic solvent (1
cal/g/oK), a higher power setting can be used to compensate
for the higher heat capacity.
125 ml toluene
1 L flask
1 L heating mantle
SP = 80oC
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 being heated), a lower
power setting gives better control.
150 ml toluene
250 ml flask
250 ml heating mantle
SP = 35oC
10 - 100 ml
(10% power)
Even though the solvent volume isn’t included in this power
setting, it should be used because low temperatures are better
regulated with less power.
Avoid switching between power levels while the controller is heating. Specifically, do not initially set the
controller on a high power level to rapidly heat the solution, then decrease the power level to the correct
setting as the solution approaches the set point. Changing power levels doesn’t damage the controller, but
it will reduce its heating performance.
Heating Equipment. Two factors need to be considered when heating equipment (ovens, hot plates,
furnaces, HPLC columns, etc.); (1) placement of the temperature sensor (Section 2.4) and, (2) the
appropriate power setting. The best guide to the correct power setting for various pieces of equipment is
the researcher's experience. If your best guess is that the equipment needs 1/3 full power to heat to the set
point, set the power switch on the 300 ml - 2 L setting (i.e., 50% power, it’s usually better to have too
much power rather than too little). If the heater heats too slow, increase the power (to the >2 L setting), if
it heats too fast or has excessive overshoot, decrease the power (to the 50 - 500 ml setting). If the amount
of power seems to be adequate, but the heater doesn’t heat with stability, the controller probably needs to
be tuned (see Section 2). Section 3.8 shows the type of performance you should expect from the
controller with different pieces of equipment.
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
controller (Figure 1; #’s 8 & 12). All thermocouples are color coded to show their type (Blue = type T;
Yellow = type K; Black = type J). The color of the thermocouple plug must match the color of the
receptacle on the front of the controller. If the thermocouple is broken or becomes unplugged, the error
message "inPt" "FAiL" blinks in the temperature meter display and the controller stops heating.
17

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
40
50
60
70
80
Co ditio s: Set poi t = 75 C
Laboratory ove
o
Power Setti g = 50 - 500 ml
Power Setti g = > 2L
Co ditio s: Set poi t = 45 C
HPLC Colum wrapped with heati g tape
Power Setti g = 50 - 500 ml
o
Temp
C
o
Time (mi )
2 0
3 0
0
5 0
6 0
7 0
8 0
0 1 0 2 0 3 0 0 5 0 6 0 7 0
Temp.
o
C
Time (mi )
Power Setti g = 10-100 ml (i.e., 10% power)
Power Setti g = 50-500 ml (i.e., 25% power)
Power Setti g = 300 ml - 2 L (i.e., 50% power)
Co ditio s: Set poi t = 70
o
C
50 ml Tolue e
100 ml Rou d bottomed flask
Graph 1
This graph shows typical
heating profiles for a laboratory
oven and an HPLC column. In
the example of the oven the
heating curves for 2 different
power levels are shown. The
50 - 500 ml setting is the
appropriate amount of power to
heat to 75oC and thus results in
a smooth heating curve. The
> 2L power setting is too much
power and results in oscillation
around the set point.
Graph 2
This graph shows the affect of
different power settings when
heating liquids with heating
mantles. The 10 - 100 ml
setting (10% power) is
underpowered and results in
slow heating. The 300 ml - 2 L
setting (50% power) is too much
power and results in sporadic
control. The controller adapts
to a wide range of power
settings. In this example the
power is varied by a factor of
5X, nevertheless, reasonable
control is maintained in each
case.
18

0 10 20 30 0 50 60 70
20
5
70
95
120
1 5
170
Temp
C
o
Time (mi )
Co ditio s: 300 ml collidi e
500 ml flask
500 ml heati g ma tle
Set poi t = 45 C
Power = 50 - 500 ml
(25% power)
o
Set poi t = 100 C
Power = 300 ml - 2 L
(50% power)
o
Set poi t = 155 C
Power = > 2 L
(100% power)
o
Graph 3
Another factor affecting the
choice of power setting is the set
point temperature. For set points
near room temperature a low
power level is adequate. For
average temperatures
(50 - 100o) the volumes printed
on the front of the controller are
a good guide. For high
temperatures, the next higher
power setting might be needed to
supply the heater with additional
power.
The output power level limits the total amount of power delivered to the heater. In this sense it works like
a variac and can be used like one. If the heater isn’t getting enough power, turn the power level up one
notch, if it’s getting too much power, turn it down.
3.9 Do's and Don'ts When Using Your Controller. The controller, heater and thermocouple form a
closed loop feedback system (see Fig. 2 in Section 4.1). When the controller is connected to a heater, the
feedback loop should not be broken at any point.
Don't remove either the thermocouple or heater from the solution without setting the 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 it heats
continuously.
Don't use the controller to regulate an exothermic process.
The controller has no capacity for cooling. If an exotherm is expected, it must be controlled in
another way.
Do use an appropriate size flask and heater for the volume being heated.
Use the smallest flask and heating mantle that accommodates the reaction. This ensures that the
heating power of the heating mantle closely matches the volume being heated. This also allows the
solution to radiate excess heat to minimize temperature overshoots.
Do place the thermocouple directly in the solution.
Place at least the first 1/4” of the thermocouple directly into the solution. If a corrosive mixture is
heated, use a coated-coated thermocouple (or use the external thermocouple method; Section 4.2).
Do avoid exposure of the controller to corrosive gases and liquids.
The atmosphere of a research hood is corrosive to all electronics. Place the controller outside the
hood away from corrosive gases.
19

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.
Procedure 4.Perform when using heating mantles with round bottomed flasks.
[This procedure takes about 2 minutes to perform]
1. Press and hold in both the and keys on the front of the temperature meter for the channel you want to change until the word “▼ ▲ tunE”
appears in the display, then release both keys.
2. Press the key once and the word “▲bAnd” will appear in the display.
First hold in the ‘*’ key, then while holding in the *’ key press the or key until the value▼ ▲
“10” appears in the display, then let go of all the keys.
3. Press the key once and the word “▲int.t” will appear in the display.
First hold in the ‘*’ key, then while holding in the *’ key press the or key until the value “▼ ▲ 10” appears in the display,
then let go of all the keys.
4. Press the key once and the word “▲dEr.t” will appear in the display.
First hold in the ‘*’ key, then while holding in the *’ key press the or key until the value “▼ ▲ 50” appears in the display,
then let go of all the keys.
5. Press the key once and the word “▲dAC” will appear in the display.
First hold in the ‘*’ key, then 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 ‘*’ key, then while holding in the *’ key press the or key until the value “▼ ▲ 30” appears in the display,
then let go of all the keys.
7. Press and hold in both the and keys until the temperature appears in the display, then release both keys.▼ ▲
3.11 Changing the Temperature Display Resolution The controller is programmed to display temperature
with 0.1oC resolution. The controller can be changed to 1oC resolution if by following the procedure
below (the display can also be changed to read in oF, call for information). There are two reasons to
change the display resolution:
1) To enter a setpoint faster (the display scrolls 10X faster in 1omode than in 0.1omode).
2) To display temperatures above 999.9o.
1. Press 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.
2. Press the key once and “▼LEVL” appears in the display.
First hold in the ‘*’ key, then while holding in the ‘*’ key press the key until “▲2” appears in the display then let go of all
the keys.
3. Press the key repeatedly until the word “▲diSP” appears in the display.
First hold in the ‘*’ key, then while holding in the ‘*’ key press the or key until the value “▼ ▲ 1” [not “0.1”] appears in
the display, then let go of all the keys.
4. Press and hold in both the and keys until the temperature appears in the display, then release both keys.▼ ▲
20