Hach 48685, Руководство пользователя

Страница: 8 / 40

Figure 3 Sample heater
The heater contains a heater module, temperature controller, temperature sensor, thermal cut-off
switch, circuit breaker and power-connection terminal. The housing consists of a gasket-sealed
plastic enclosure.
A single piece of stainless steel tubing cast in an aluminum block and two 700 watt electric heater
elements make up the heater module. The stainless steel tube has two stainless steel adapter fittings
brazed on each end.
The temperature controller is a Watlow EZ-ZONE PM Express with microprocessor-based auto-
tuning control.
Figure 3 shows the normal operating display, the control panel and the controller keys, and describes
the controller key functions.
The lower window displays the set-point temperature and the upper window displays the process
temperature. The operator enters the setpoint and the controller heats the sample to the setpoint.
The 1 indicator light is on when the heating element turns on. A thermocouple attached to the outlet
tube of the heater module makes up the temperature sensor. The sensor indicates the sample
temperature at the outlet. A thermostat mounted on the heater block protects the product and user
from a thermal run-away fault (
Wire the instrument on page 11).
English 7