PCB Piezotronics ICP RHM240A01 Installation And Operating Manual page 8

ICP
4.0 OPERATION
4.1 TYPICAL ICP SYSTEM CONFIGURATION
Sensors with built-in ICP circuitry require a constant-current
excitation voltage for operation. The enclosed Specification
Sheet provides specific power requirements. Required supply
voltage is normally 20 to 30 VDC, while the constant current
required ranges from 2 to 20 mA.
PCB standard battery-powered signal conditioners are factory
set at 2 mA and may be used to adequately drive a signal for
100 feet. PCB line signal supplies are factory set at 4 mA (and
adjustable from 2 to 20 mA), enabling signals to be transmitted
over hundreds of feet.
It is necessary to supply the sensor with a 2 to 20 mA constant
current at +20 to +30 VDC through a current-regulating diode
or equivalent circuit, contained in all PCB signal conditioners.
See Guide G-0001B for powering and signal conditioning
information pertaining to all ICP
Most of the signal conditioners manufactured by PCB have an
adjustable current feature allowing a choice of input currents
from 2 to 20 mA. In general, for lowest noise (best
resolution), choose the lower current ranges. When driving
long cables (to several thousand feet), use the higher current,
up to 20 mA maximum. Consult the factory to determine if
higher current settings are required. Connect the sensor to the
power unit as shown in the typical ICP
As displayed in Figure 4.1, operation requires the connection
of the strain sensor first to a signal conditioner, then to a
readout device (oscilloscope, meter, recorder, or A-to-D
board) or to a readout device with built-in ICP sensor
excitation. Tighten the coaxial cable to the sensor by hand to
ensure good electrical contact.

QUARTZ STRAIN SENSOR OPERATION MANUAL
®
instrumentation.
®
sensor systems below.
Standard
Sensor Cable or
Output Cable
ICP® Strain
Sensor
Standard
Sensor Cable
ICP® Sensor
ICP® Strain
Signal
Sensor
Conditioner
®
Figure 4.1 Typical ICP System Configurations
3
Readout Device with
Built-in ICP®Sensor Excitation
(not supplied)
Output
Cable
Readout Device
(not supplied)