User manual

Digital BUS-WATCH®

Radio Engineering Industries, Inc.

640289

Rev B -- 11/18/2002

Calibration Screen

This submenu screen has two different options, Speedometer Calibration, and Voltage

Calibration.

Note: To use these functions, you must have the DISPLAY OPTIONS set to display the

Speedometer and/or the Voltage.

SPEEDOMETER CALIBRATION

Because speedometers can vary greatly among bus manufacturers, the Digital

BUS-WATCH® has the ability to calibrate its own speedometer to that of the bus.

Follow this procedure to calibrate the speedometer:

• Drive the bus at a known and constant speed, such as 30 mph.

• Bring up the Speedometer Calibration Screen. The screen will display what the

Digital BUS-WATCH® system perceives as the vehicle's speed.

• Use the UP and DOWN arrow keys to adjust the displayed speed to match that

the vehicle's speedometer. This might require many keypresses.

• When the speeds match, press EXIT to save the calibration and return to the

previous menu. The displayed speed will now match that of the vehicle.

Figure 13

VOLTAGE CALIBRATION

It is sometimes useful, mainly for troubleshooting purposes, for the Digital BUS-

WATCH® to record the voltage on the power system of a bus. The unit has a

voltage sensor that can record the current voltage supplied to the unit by the bus.

However, the wiring systems of buses often vary greatly among manufacturers, so

the Digital BUS-WATCH® has the ability to calibrate its own voltmeter. Follow this

procedure to calibrate the voltmeter:

• Use a handheld voltage meter to sense the voltage supplied to the power inputs

of the Digital BUS-WATCH®.

• Bring up the Voltage Calibration Screen. The screen will display what the Digital

BUS-WATCH system perceives as the voltage supplied.