MULTICHANNEL SIGNAL CONDITIONER MODEL 482C27 GENERAL OPERATION MANUAL
19
Pressing ENTER brings up a submenu that allows the operator to continue the save settings operation by selecting
‘Execute’ or ‘Cancel.’ Both options return control to the main menu. If ‘Execute’ is selected then the settings on all 4
channels are saved and used as the default settings when the unit is powered on. Selecting ‘Cancel’ will cancel the
operation.
Save Settings
EXECUTE
21) Options that are not included and/or installed
For any selected option not actually included in model 482C27, an ‘option not installed’ message is shown on the
display. When the ENTER button is pressed, the following is shown:
Option not
installed
Reference
3-0.
THEORY OF OPERATION
3-1.
Sensor Excitation
ICP®
refers to a voltage mode sensor that combines an integrated circuit and a piezoelectric sensing element in a single
housing to provide a low impedance voltage output. The sensor is powered by a +24 VDC power supply having a typical
constant current of 2 to 20 mA (current can be fixed or variable depending on the signal conditioner model).
Sensor excitation occurs as the constant current of all channels are set. Model 482C27 allows the constant current to be
adjusted between 1 and 20 mA to provide the required excitation for most applications. Special situations, such as
driving extra-long cables (more than 1000 ft) with high frequency or fast rise time pulses, may require increasing the
drive current to 12 mA or higher.
Figure 2 ICP
®
Sensor Excitation
When driving fast rise time pulses over long lines, system performances can be optimized by “tuning” the drive current
to the line; i.e. by finding the best current setting for the particular test of physical parameters. To determine the optimal
current setting, experiment with your particular test set up. To insure optimal accuracy in constant current adjustment,
make sure all channels have sensors or simulated loads, similar to the one provided by model 401B04 (ICP® sensor
simulator).
