Ratek TH8500 Programmable Immersion Heater Circulator - User Manual
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For best results, a Ratek insulated water bath should be used, as well as a lid to reduce evaporation and heat
loss.
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Note:
It is normal for the temperature to exceed the set point slightly whilst the temperature in the bath
stabilizes. The bath temperature will drop back down to the set temperature and then the proportional
temperature control will attempt to maintain the set temperature.
Operating a Ramping
Profile
The TH8500 has the ability to store up to 9 “Profiles”. A profile is a collection of temperature set-points and/or
dwell (idle) periods that you wish the controller to achieve during unattended operation. For example, you may wish
the temperature controller to reach 37° operation, hold this temperature for one hour and then ramp the
temperature up over the next 30 minutes to 50° and then hold that temperature for 2 hours. The 37° and 50°
targets are referred to as “Program Segments”.
Each profile may contain multiple segments, however the 9 profiles are broken into 3 types, each of which has a
different segment storage capacity as below. You should choose an appropriate profile number based on the
maximum number of segments your profile will require.
Profile Numbers
Maximum Number of Segments
1 thru 4
16
5 thru 7
32
8 and 9
64
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To configure and store a profile, first determine the most suitable profile number based on the table above.
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For each “Segment” you wish to program, you will be prompted to configure the following parameters (depending
on the segment type (SGTY) not all parameters will be applicable).
- The holdback band in °C. If the holdback feature is enabled and the current temperature
falls outside the band of the desired temperature (deviation from the set point), the unit will enter
holdback mode until the current temperature is back inside the holdback band.
- The starting set point temperature for the profile in °C. This can only be configured for
segment zero (0). This temperature will serve as the initial set point value for the profile and
ramping will be calculated relative to this set point. To ensure the actual bath temperature
matches the starting temperature of the profile, before running the profile set the desired starting
set point in static mode and allow the bath to stabilise.
- The unit of measurement for the ramp rate :
- Hours & Minutes
- Minutes & Seconds
- °C Per Minute
- °C Per Hour
- The unit of measurement for the dwell period :
- Hours & Minutes
