Payload Meter III - Section 60 08/06 OM6008 Page 60-6 COMPONENT DESCRIPTION System Diagram Suspension Pressure Sensors Operator Display PLM III uses a two-wire pressure sensor. The range for the pressure sensor is 281 kPa (4000 psi) and the overload limit is 700 kPa (0000 psi). One wire to the sensor is the supply voltage and the other is the sig- nal. The 0-4000 psi range is converted into an electri- cal current between 4-20 ma. The supply voltage for the sensor is nominally +18 VDC. Each pressure sensor has an 3000 mm (118 in.) length of cable. The cable is specially shielded and reinforced to provide mechanical strength and electronic noise immunity.
The speedometer/display gauge is used as a speed- ometer and payload display. The top display is used for speed and can display metric (km/h) or English (mph) units. Grounding terminal #4 on the back of the speedometer will switch the meter to display met- ric units. Leaving terminal #4 unconnected will cause the gauge to display English units. The speedometer can be adjusted using a calibration potentiometer in the back just like existing speedometers. The payload meter uses the lower display for pay- load information. The normal display mode shows the current payload. The display can be changed to show the load and total tons counter or the operator ID.
Using the operator switch on the dash panel, the current suspension pressures and incline can be dis- played. The units for display are set using the PC software. Payloads can be displayed in short tons, long tons, or metric tons. Inclinometer The inclinometer is used to increase the accuracy of load calculations on an incline. The inclinometer uses three wires. For the sensor, red is the +18 VDC supply voltage, black is ground, and the white is the signal. The incline signal is a voltage between 1 and 4 volts. Zero degrees of incline is represented by 2.6 VDC on the signal line. The voltage signal will be decreased by 0.103 VDC for every degree of nose up incline.