Lake Shore 370, Руководство пользователя

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Lake Shore Model 370 AC Resistance Bridge User’s Manual
4.11.2.6 Heater Output Display
The heater output or control output is a variable DC current source with several ranges to accommodate different loads.
The Model 370 can be configured to display the output range as its full scale current and the output as a percent of that
current. This configuration is helpful in setup and tuning of a control system but does not provide good information on
power entering the load. The instrument can also be configured to display the output range by its full scale power and the
output as power in watts. This configuration is better for predicting the power entering the load but it relies on an
accurate heater resistance being entered into the instrument, refer to Paragraph 4.11.2.7. The manual output parameter
also follows this units setting.
The next control setup screen appears as a prompt for the heater output display to be in current or power.
Control Setup
Select With °®
Heater Display: Current
Use the
s
or
t
key to select heater output display as current or power. Press
Enter
to accept the new selection and
continue to the next setting screen. Press
Escape
to cancel the new selection and return to the normal display.
4.11.2.7 Heater Resistance
The Model 370 does not need to know heater resistance to perform control its control functions. Heater resistance is only
required to accurately display the heater output and manual output in power. The instrument does not measure heater
resistance so one must be entered for these display values to be meaningful. A 100
Ω heater is required for maximum
power output but other values can be used. If a heater resistance is not known, the heater output display should be
configured for current.
The next control setup screen appears as a prompt for the heater resistance.
Control Setup
Enter A Value For
Heater Resistance: 100.00 ¦
Use the data entry keys to enter a heater resistance between 1 and 100,000 ohms. Press
Enter
to accept the new selection
and continue to the next setting screen. Press
Escape
to restart the setting sequence and enter a new value. Press
Escape
again to cancel the sequence and return to the normal display.
4.11.2.8 Heater Range Limit
The one watt maximum heater output power available from the Model 370 can be far too much for some loads. The
heater range limit parameter allows the user to lock out higher heater ranges so they are not accidentally selected from
the front panel. The limit setting represents the highest allowable heater range and is always set in current. To disable the
control output entirely, refer to Paragraph 4.11.1.
The next control setup screen appears as a prompt for the heater range limit.
Control Setup
Select With °®
Heater Limit: 100mA
Use the
s
or
t
key to select a heater range limit from 100 mA to 31.6
μ
A as limit. Press
Enter
to accept the new
selection and continue to the next setting screen. Press
Escape
to cancel and return to the normal display.
4-18 Operation