Stirring; Power; Heater - Fluke 7341 User Manual

7341 Calibration Bath
User's Guide
8.2
8.3
8.4
34
Flash Point: The point at which ignition may occur. The point shown may be
either the open or closed cup flash point. Refer to the flash point discussion in
Section 8.1.8, Safety.
Boiling Point: At or near the boiling point of the fluid the temperature stability
is difficult to maintain. Fuming or evaporation is excessive. Large amounts of
heater power may be required to maintain the temperature because of the heat
of vaporization.
Decomposition: The temperature may reach a point at which decomposition of
the fluid begins. Further increasing the temperature may accelerate decomposi-
tion to the point of danger or impracticality. Silicone oils can oxidize, causing
the fluid to thicken. Replace at the first sign of increasing viscosity.

Stirring

Stirring the bath fluid is very important for stable temperature control. The
fluid must be mixed well for good temperature uniformity and fast controller
response. The stirrer is precisely adjusted for optimum performance.

Power

Power to the bath is provided by an AC mains supply. Refer to Section 3.1,
Specifications, for power details. Refer to and read the CAUTION at the front
of the manual concerning brownout and over voltage protection. Check the
back panel label for the correct voltage and frequency prior to energizing
the bath. Power to the bath passes through a filter to prevent switching spikes
from being transmitted to other equipment.
To turn on the bath press the control panel power switch to the ON position.
The stirring motor will turn on, the LED display will begin to show the bath
temperature, and the heater will turn on or off until the bath temperature
reaches the programmed set-point.
When powered on, the control panel display will briefly show a four digit num-
ber. This number indicates the number of times power has been applied to the
bath. Also briefly displayed is data, which indicates the controller hardware
configuration. This data is used in some circumstances for diagnostic purposes.

Heater

The temperature controller precisely controls the bath heater to maintain a con-
stant bath temperature. Power is controlled by periodically switching the heater
on for a certain amount of time using a solid-state relay.
The front panel red/green control indicator shows the state of the heater. The
control indicator glows red when the heater is on and green when the heater is
off. The indicator pulses at a constant rate when the bath is maintaining a stable
temperature.