Barnstead International MIRAK 725 Series, Инструкция по эксплуатации и список запасных частей

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maintain a precise setpoint we recommend using a probe
to control the solution temperature instead of controlling
the top plate temperature.
When using a probe with your MIRAK hot plate or stirring
hot plate it is recommended that you use a clamp on a
support rod to hold the probe in your solution.
To ensure accurate probe readings, as much of the probe
sheath as possible should be immersed in your solution.
If the probe is plugged into your hot plate or stirring hot
plate while the heat control is operating but is not in solu-
tion, the temperature display will continue to indicate an
ambient temperature. Because the set point cannot be
reached the element will continue to supply heat to the
top plate, and the maximum top plate temperature of
540°C may be reached.
To obtain an accurate reading when you are using the
probe and stirring your solution, make sure the probe is
immersed in the liquid and is not located in air in the cen-
ter of the stirring vortex. Drafts and other temperature
fluctuations will affect temperature accuracy.
Calibrating the Probe
Temperature Input
To verify the temperature reading of the probe, insert a
calibrated thermometer into a solution you are heating on
the stirring hot plate. When the thermometer reading has
stabilized, record the temperature readings given by both
the thermometer and by the probe as indicated on the
MIRAK display.
To calibrate the probe:
1. Unplug unit, turn unit upside down and remove
screws from bottom.
2. Open unit. Locate the logic board. (See illustra-
tion of interior of unit or the exploded view).
Move the jumper from position J11 to position
J1. For 100 and 120 volt units, you must remove
jumper J3 if it exists.
3. Replace the bottom of the unit and turn the unit
over.
13
O
PERATION
Warning
If the probe is plugged into your stir-
ring hot plate while the heat control is
operating but is not in solution, the
temperature display will continue to
indicate an ambient temperature.
Because the setpoint cannot be
reached, the element will continue to
supply heat to the top plate, and the
maximum top plate temperature of
540°C may be reached. Any type K
thermocouple probe used must be an
ungrounded type.
Note
The top plate temperature will not
exceed the 540°C maximum.
Note
The following procedure can be performed
only on units with serial numbers greater
than the following:
7" Hot Plates .... 726931000000
7" Stirring Hot Plates ... 727931000000
12" Hot Plates ...729931000000
12" Stirring Hot Plates ... 730931000000