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Find
answers for the most frequently asked questions about our products and
applications. 1. What is working temperature range?
2. What is operating temperature range?
3. What is temperature stability?
4. What is temperature uniformity?
5. What advantages are featured by JULABO displays?
6. JULABO high end products feature the VFD
COMFORT-DISPLAY.
7. Which JULABO units feature interactive operator
assistance?
8. What is the difference between PID and ICC
temperature control?
9. What benefits do the ‘TCF‘ Temperature Control
Features offer?
10. What tasks are done by JULABO pumps?
11. What has to be considered when using RS232
interfaces?
12. Which refrigerants are used by JULABO?
13. What is the meaning of ‘ACC‘ Active Cooling
Control?
14. What does proportional cooling control mean?
15. Which advantages are featured by JULABO early
warning systems (patented)?
16. Why can temperature alarm indications be set to
automated cut-off?
17. Which norms and standards do JULABO units
comply with?
18. What does the classification according to DIN
12876-1 indicated on the type label mean?
19. What does JULABO offer beyond DIN?
20. What are permissible ambient conditions for
JULABO units?
21. Which mains voltages and frequences are
permissible?
22. What is the warranty time given by JULABO?
23. What has to be taken into account when
connecting an external system?
24. Which advantages does metal tubing have?
25. Which bath fluids should be used?
26. Are cool-down and heat-up times shorter when
using JULABO THERMAL bath fluids instead of water and alcohol?
27. How do you calculate the required cooling or
heating capacity?
28. What about the JULABO online remote diagnosis
with ‘black box’ function?
29. Why do some circulators have pumps with just pressure ratings, and
others have pumps with pressure and suctions ratings?
30. What is CE approval?
31.
What is the difference between temperature accuracy and
temperature stability?
32. At what ambient conditions are Julabo units tested to determine
product specifications?
33. What types of materials are the baths constructed of?
34. What is the difference between the Pt100 sensor and thermocouples?
35. What is the difference between specific types of thermocouples (J,
K, R, S, T)?
36. What is full range (or active) cooling? What are its benefits?
37. What types of RTD's are compatible with JULABO units?
38. What should be done to optimize temperature control with my
chiller, heater or circulator?
39. Why does the circulator go to reset
when the compressor of the cooling unit is switched on?
40. What protection does the fuse provide
in the Unit itself?
41. What considerations are there when
choosing bath fluids for a JULABO Unit?
42. If the message ‘Cerr’ occurs when
switching on a new Cooling Unit, what can I do?
43. During heating a bath filled with oil,
the error message ‘E06’ (sensor alarm) appears, what can be checked?
44.
A unit in the TopTech Series (MP, MD,
MV or MW) shows the message ‘E06’ which changes to ‘E01’ after a
time, what should I do?
45. The unit is alarming and I have tried
resetting the alarm by turning the unit off and on, but the alarm is
still indicated, what can I do?
46. While heating up the bath, by using
JULABO Thermal Bath Fluid, for a short while oil bubbles out of the
bath.
47. Which Bath Fluid is recommended for
my application?
48. What different types of tubing are
offered by JULABO?
49. What are the advantages of using a HT Circulator
with a C.U. Cooling Unit?
1. What
is working
temperature range?
Working temperature range is
the range within the operating temperature range which can be
reached by the circulator itself and without external cooling,
based on an ambient temperature of +20 °C.
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2. What is operating
temperature range?
Operating temperature range is the temperature range
limited by the controlelectronics. E.g. working temperature range
of heating circulators can be extended by auxiliary means down to
the maximum of the lower operating temperature range.
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3. What is temperature
stability?
Temperature stability is the maximum temperature difference
at one specific measuring point in the circulator bath.
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4. What is temperature
uniformity?
Temperature uniformity is the maximum temperature
difference at different measuring points in the circulator bath.
This is especially important for calibration tasks (page 38, 39).
In JULABO circulators tem-perature uniformity differs only
slightly from temperature stability. Visco baths and calibration
baths offer the best temperature uniformity.
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5. What advantages are
featured by JULABO displays?
JULABO LED displays are visible at large distances and from
every angle.
MULTI-DISPLAY (LED) refers to the possibility
of not only displaying actual and setpoint values, but also values
for high / low temperature warning and high temperature cut-off.
Additionally the MULTI-DISPLAY (LED) enables the indication of
the desired pump stage in circulators with electronically adjustable
pumps and the display of the shaking frequency in shaking water
baths.
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6. JULABO high end
products feature the VFD COMFORT-DISPLAY.
This display aims at providing even more illuminating power,
clearness and brilliance as well as an even easier operator
assistance. It features the unique simultaneous indication of
three temperature values: Internal actual temperature, setpoint
temperature and external actual temperature are permanently
displayed. Furthermore the selected pump stage is visible at all
times on the integrated illuminated pump stage display.
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7. Which JULABO units
feature interactive operator assistance?
JULABO circulators of the 'HighTech' Series, the high
dynamic temperature systems 'Presto' and 'Forte HT' as well as LC6
programmable controller feature additionally a 4-line backlit and
interactive LCD DIALOG-DISPLAY for user-friendly operation.
Besides actual and setpoint values it is possible to indicate, for
example, the control mode (internal/external), heating or cooling
capacity as well as external setpoint values.
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8. What is the difference
between PID and ICC temperature control?
JULABO PID1, PID2 and PID3 controllers have fixed control
parameters (Xp, Tn, Tv). These can be changed manually in PID2 and
PID3 controllers in order to get an improved temperature stability
especially in external operating mode.
ICC (Intelligent Cascade Control) currently
represents the world’s most advanced and absolutely unique
temperature control system. ICC features perfect temperature
control through automatic and self-optimizing adjustment of PID
control parameters according to the application.
ICC temperature control is featured in JULABO
circulators of the ‘HighTech‘ series, high dynamic temperature
control systems and the LC6 programm-able controller.
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9. What benefits do the
‘TCF‘ Temperature Control Features offer?
a) Band limit: When working in external control mode
this function allows the user to limit the difference between
internal and external temperature to freely selectable values.
Advantage: Protection of the temperature controlled equipment
through careful temperature application, protection of e.g. glass
reactors from thermal shock.
b) Dynamics: Option to choose between
aperiodic and normal PID behavior when using internal control
mode:
Aperiodic (default value): Perfect, but takes
slightly longer to reach the setpoint without overshoots.
Normal: Reaches the setpoint fast, but with small
overshoots. The same applies to refrigerated circulators (undershoots).
c) Limit settings: The limits ‘IntMax‘ and
‘IntMin‘ are applicable when operating in external control mode.
Fixed temperature limits (maximum and minimum values) can be set for
the internal bath temperature. These limits cannot be exceeded by
the controller.
d) Co-speed factor: this parameter
influences the time for reaching the setpoint temperature when
working in external control mode. Increasing the Co-speed factor
reduces the time for reaching the setpoint, but the possibility of
overshoots increases.
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10. What tasks are done
by JULABO pumps?
JULABO uses immersion pumps which are designed to work free
from mechanical and thermal wear over extended time periods. The
main task, beside the internal circulation of the bath fluid, is
to constantly supply objects or systems with bath fluid in a
closed or open loop. The units of the ‘Economy‘ and ‘TopTech‘
series, as well as JULABO recirculating coolers, feature pressure
pumps of different capacities for closed external systems (loop
circuits).
The models MC, ME and ‘Presto‘ feature
electronically adjustable pump capacities in stages.
All circulators of the ‘HighTech‘ series feature
pressure and suction pumps which can also be adjusted electronically
in stages. These pump systems can achieve remarkable pressure,
suction and flow rate capacities in closed or open external systems.
When working with connected external glass equipment (autoclaves,
reactors) the advantage is that by adjusting maximum pressure,
damage to the glass vessel can be avoided.
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11. What has to be
considered when using RS232 interfaces?
It is important to use a null-modem cable to enable
communication between the PC and the JULABO unit. RS232 interface
cable and USB interface adapter cable are available as accessories.
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12. Which refrigerants
are used by JULABO?
For more than 10 years JULABO refrigerating systems have
been filled exclusively with CFC-free refrigerants.
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13. What is the meaning
of ‘ACC‘ Active Cooling Control?
The ‘ACC‘ range is the working temperature range in which
the refrigeration system remains active as long as refrigeration
is desired or required. All JULABO units feature working
temperature ranges which correspond to the ‘ACC‘ ranges. Thus the
refrigeration system can also be used at high temperatures (e.g.
+200 °C) for fast cool-down.
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14. What does
proportional cooling control mean?
Refrigerated units without proportional cooling have
refrigeration systems which are either switched on or off. This
means they are either working with 100 % or 0 % cooling power.
Systems with proportional cooling have a special electronic valve
which can automatically control cooling capacity between 0 % and
100 %. This allows for accurate control of required cooling power
at any temperature and at the same time saves energy.
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15. Which advantages are
featured by JULABO early warning systems (patented)?
The reason for an untimely cut-off caused by the low liquid
level protection is a lack of bath fluid. Usually processes
involving temperature application should not be interrupted in
order to avoid major damages (e.g. when incubating in the
circulator bath or when applying temperature control externally to
a reactor).
The early warning system for low liquid level
indicates through an intermittent signal tone that bath fluid has
to be refilled.
Furthermore an undesired change of the set actual value, e.g.
through an exothermic reaction, can be detected and indicated
acoustically. For this purpose limit settings, e.g. 2 °C above and
below the actual temperature are set via the display. When there is
a warning counter-active measures can be taken.
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16. Why can temperature
alarm indications be set to automated cut-off?
This is required for special applications, but can be
switched back to the normal warning function at any time. Changing
to cut-off is especially popular in low temperature ranges in
order to use this function as a low temperature cut-off with
permanent signal tone.
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17. Which norms and
standards do JULABO units comply with?
Of course all JULABO units are CE certified and comply with
the safety requirements. JULABO units comply with the following
harmonized norms: EN 1050, EN 292, EN 61010, EN 60204, EN 563, EN
61326.
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18. What does the
classification according to DIN 12876-1 indicated on the type
label mean?
Terms and classifications are specified in DIN 12876 and
provide information on the application. JULABO units belong to the
following classification:
Class I: (JULABO abbreviation ‘S1‘): Units of
this class feature a fixed high temperature or dry-running
protection. The units are only suitable for operation with
non-flammable bath fluids.
Class III: (JULABO abbreviation ‘S3‘): Units of
this class feature adjustable high temperature cut-off and
additional low liquid level protection. The units are suitable for
operation with flammable bath fluids.
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19. What does JULABO
offer beyond DIN?
•
High
temperature cut-off is adjustable in all circulators. It is
indicated on a display (MULTI-DISPLAY LED / VFD COMFORT-DISPLAY)
and can be accessed at any time.
• If the set high temperature value or an
impermissible low liquid level is detected an optical indication
appears and an audible signal sounds permanently.
• All JULABO units include a constant monitoring
of the difference between safety and working temperature sensor
which cuts-off the unit if the difference between these two sensors
exceeds 25 K. The cut-off is also effected in case one of the two
sensors is defective and has to be replaced. The safety sensor has
an additional function as a dry-running protection.
•
Furthermore a plausibility
control of both sensors through software is always active.
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20. What are permissible
ambient conditions for JULABO units?
All JULABO units can be operated failure-free at ambient
temperatures between +5 and +40 °C (max. +35 °C for ultra-low
refrigerated circulators). Optimal ambient conditions are ambient
temperature of +20 °C and approximately 50 % relative humidity.
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21. Which mains voltages
and frequences are permissible?
Information on mains voltages and net frequencies required
for safe operation can be found on the type label of each unit.
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22. What is the warranty
time given by JULABO?
Warranty time for proper operation of all units is 12
months. The 1PLUS-Warranty provides the user with a free extension
of warranty time to 24 months, limited to a maximum of 10,000
operating hours. The registration for the 1PLUS-Warranty can be
done at www.julabo.de!
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23. What has to be taken
into account when connecting an external system?
1. Tubing between the circulator and the external system
has to be kept as short as possible and has to be secured to
prevent slipping off.
2. Tubing, connections and external system have to be well
insulated.
3. Use of a suitable JULABO bath fluid.
4. The exchange of energy between the circulator
and the external system has to be optimized (e.g. by avoiding
strictures in the tubing).
5. When using an external temperature sensor it has to be well
integrated into the system.
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24. Which advantages
does metal tubing have?
Flexible JULABO metal tubing can be connected with the
circulator and the external system thus avoiding slipping. The
integrated insulation avoids loss of performance.
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25. Which bath fluids
should be used?
For working temperature ranges up to +80 °C JULABO
recommends the use of de-ionized water. Distilled water tends to
take in composites from components thus causing corrosion.
JULABO THERMAL bath fluids offer extended
temperature ranges. They have the advantage of much smaller
specific heat capacities. When selecting bath fluids special
attention has to be paid to the flash point and fire point.
Especially when it comes to low temperatures the
permissible viscosity as stated in the operating manuals may not be
exceeded.
Alcohols, e.g. ethanol, only have a limited range of applications
due to their extremely low fire point.
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26. Are cool-down and
heat-up times shorter when using JULABO THERMAL bath fluids
instead of water and alcohol?
The required cooling/heating capacity in Watts or Kilowatts
is less when using silicon oils (THERMAL). Therefore heat-up and
cool-down times are shorter. The reason is that THERMAL bath
fluids have smaller specific heat capacities than water and
alcohol.
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27. How do you calculate
the required cooling or heating capacity?
The following formula can be used for a time-dependent
calculation:
Q = (m * c* dT) / t
Q = required cooling/heating capacity in
kW
m = mass of material in kg
c = specific heat capacity (water = 4.2 /
Ethanol = 2.5 / silicon oil = 1.8) dT = required temperature
difference in °C
t = desired cool-down / heat-up time in
seconds
One has to take into consideration that the total
mass m is the sum of the volumes of different sources: e.g. the
volume of the circulator, in the tubing, in the reactor’s jacket, in
the reactor.
The simple calculation of required cooling/heating
capacity as seen above does not take into account differences in
weight of the bath fluids or other factors reducing performance.
Loss of performance is caused e.g. by: tubing (length, insulation),
jacketed baths/reactors (material, thickness, surface), high ambient
temperatures, open applications (surface). To allocate sufficient
cooling / heating capacity a safety factor of 20-30 % should be
integrated into the calculation.
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28. What about the
JULABO online remote diagnosis with ‘black box’ function?
The new circulators with RS232 interface feature a special
function to support the enduser. During operation a black box
which is integrated in the circulator works unnoticed and
invisible in the background recording all relevant data of the
last 30 minutes. In case of a problem this data can be downloaded
via software from the circulator to the PC and sent to JULABO by
e-mail. Based on this data fast and efficient support can be
provided. The software ‘EasyBlack Box’ is available as a free
download at www.julabo.de.
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29. Why do some circulators have pumps with just pressure ratings, and
others have pumps with pressure and suctions ratings?
Some Julabo circulators (EC, MP, and MD, for example)
have a single centrifugal pump. This pump draws fluid from the
bath tank and circulates it externally. If no external system is
connected, the pump can be adjusted to circulate internally. Other
Julabo circulators (MW, HE, HD, HP, SD, SP, TD, and TP, for
example) have two centrifugal pumps. One is set up to circulate
fluid from the tank externally, while the other is designed to
circulate fluid from the external system to the bath tank. In
other words, there is a pressure pump and a suction pump. Each
pump has its own ratings. When used in combination, the pumps can
provide even higher flow rates than using either single pump alone.
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30. What is CE approval?
CE stands for "Electromagnetic Compatibility".
It is the European safety standard for electronic components,
which contains requirements similar to FCC, UL, and CSA standards
in North America.
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31.
What is the difference between temperature accuracy and
temperature stability?
Accuracy is simply the deviation between a measured
value and the actual value. In the case of Julabo circulators, the
accuracy would be the deviation between the displayed bath
temperature and the actual bath temperature. Stability is the
maximum deviation from a nominal value over time. For Julabo
circulators, temperature stability is the maximum deviation from
the setpoint once steady state has been reached.
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32. At what ambient conditions are Julabo units tested to determine
product specifications?
All Julabo units are tested at ambient conditions of 20°C
and 50% relative humidity. All catalog specifications are derived
from these results.
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33.
What types of materials are the baths constructed of?
AISI Stainless Steels 304, 304L, 316, and 316L.
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34. What is the difference between the Pt100 sensor and thermocouples?
There are several differences. Pt100 sensors are
actually RTDs (resistance temperature detectors), which are
usually more accurate than thermocouples, but generally have a
smaller operating range. Thermocouples are usually cheaper, and
measure temperatures as a function of voltage across the union of
two dissimilar metals. RTDs are more stable, and measure
temperatures as a function of the resistance of a particular metal
at the temperature being measured.
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35. What is the difference between specific types of thermocouples (J,
K, R, S, T)?
All of the thermocouple types function in the same
manner. The only real difference is in the construction and the
temperature vs. voltage relationships. The construction of the
thermocouple involves the use of two dissimilar metals. Depending
on which metals are used, temperature ranges and accuracies (as
well as cost) can vary greatly.
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36.
What is full range (or active) cooling? What are its benefits?
Full range cooling simply means that the refrigeration
system in a particular unit can and will operate throughout the
entire range of temperatures that the circulator is rated for.
Many suppliers limit their refrigeration systems to low
temperatures only, because their refrigeration components will be
damaged if exposed to high temperatures. JULABO systems that
feature full range cooling can safely operate at the highest
temperature the circulator is rated for. Full range cooling
greatly decreases cooling times from high temperatures.
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37. What types of RTD's are compatible with JULABO units?
100 Ohm Platinum RTD's, with European Alpha (American
Alpha will work, but with degraded results). European Alpha is
also referred to as DIN 00385.
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38.
What should be done to optimize temperature control with my
chiller, heater or circulator?
Insulate well, minimize the distance from the Julabo
unit to the application, increase the flow by using the maximum
diameter tubing, and use an external probe where possible.
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39. Why does the circulator go to reset
when the compressor of the cooling unit is switched on?
There may be a reduction in the power supply due to an
unstable network. This may cause the compressor to draw excess
current for a short period. This power reduction results in the unit
being supplied with insufficient power supply, thus triggering the
reset
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40. What protection does the fuse provide
in the Unit itself?
The fuse provided in the unit is larger than the
consumption of current, required by the Unit. The size of the fuse
is shown on the label with the unit. Please note that when the unit
is first switched on it can draw extra current for a short while.
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41. What considerations are there when
choosing bath fluids for a JULABO Unit?
The viscosity of the fluid should not be higher than
30 cSt at the lowest operable temperature. Fluids containing water
should also not be used. If fluids with higher viscosity or those
containing water are used the lowest possible temperature achievable
by the bath will not be reached. Specifications of all JULABO
refrigerated baths are determined with the use of a 97% purity
Ethanol.
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42. If the message ‘Cerr’ occurs when
switching on a new Cooling Unit, what can I do?
Check the Control Cable (grey) is connected between
the Circulator and Cooling Unit. This cable provides the signal
connection between both units. The cable is packed in a separate
box.
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43. During heating a bath filled with oil,
the error message ‘E06’ (sensor alarm) appears, what can be checked?
Check the temperature range of the oil being used. If
a different fluid other than supplied by JULABO is being used, check
the viscosity of the fluid at ambient temperature. If the viscosity
between the range of 20 to 40°C exceeds 30 cSt the pump will be
overstressed. Using bath fluids other than those provided by JULABO
may invalidate the warranty of the unit.
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44. A unit in the TopTech Series (MP, MD,
MV or MW) shows the message ‘E06’ which changes to ‘E01’ after a
time, what should I do?
Check the fluid is at the correct level in the bath, if too
low the low-level liquid adapter will trigger these error messages.
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45. The unit is alarming and I have tried
resetting the alarm by turning the unit off and on, but the alarm is
still indicated, what can I do?
After a reset, wait approximately 5 seconds, whilst the Unit
is in the switched off mode then switch back on via the main switch.
This should delete the alarm memory.
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46. While heating up the bath, by using
JULABO Thermal Bath Fluid, for a short while oil bubbles out of the
bath.
Often volatile components escape as gas phases of the
fluids, when heating up the bath fluid for the first time. This is
harmless and only happens once, whilst the bath liquid is being
de-gassed.
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47. Which Bath Fluid is recommended for
my application?
Recommendations are given in the operating
manuals for the Unit. The bath desired temperatures determines the
type of bath fluid recommended:
- Between +5°C and +90°C water can be used
- Up to -20°C a water-glycol mixture (ratio 1:1) can be used
- When choosing silicone oil, the maximum working temperature
must be a minimum of 30°C below the flash point of the fluid. At
the minimum working temperature the fluid should have a viscosity
greater than 30cSt.
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48. What different types of tubing are
offered by JULABO?
JULABO offer a variety of different types of tubing to
suit applications:
- CR (Chloroprene) Tubing (-20° to +120°C) suitable up to max
0.8 bar pressure
- Viton Tubing (-50° to 200°C) suitable for maximum 0.8 bar
pressure
- Triple Insulated Tubing (-100° to +350°C) suitable for maximum
3.8 bar pressure
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49. What are the advantages of using a HT
Circulator with a C.U. Cooling Unit?
The C U Cooling Unit allows the bath
temperature to be cooled down at a very fast rate. The amount of
cooling water used in the C.U. Cooling Unit is controlled i.e.
cooling water is only supplied as and when required. top
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