Stroboscope

Figure 2-8.—Locations for taking crankshaft deflection readings. Most borescopes have the following basic components: 1. Eyepiece (zoom or wide angle) 2. Scan control ring 3. Probe tube 4. Scan mirror 5. Quartz-lined lamp 6. Focus control ring 7. Other electrical accessories As with any optical instrument, you should handle the borescope with care to avoid damaging its lenses and mirrors. The borescope is powered by alternating current. So, before you first use it, be sure to read and follow the manufacturer’s operating instructions. The borescope can be inserted through any engine opening, such as a cylinder port, to identify problems, such as cracked pistons, cracks in the cylinder head, burned valves, and scuffed or pitted liners. You can remove the crankcase cover to inspect the bottom section of the engine. STROBOSCOPE A stroboscope is a flashing light source used to measure the speed of fast-moving objects. it produces the optical effect of stopping or slowing down an object to allow you to observe and analyze the object’s motion. Figure 2-10 shows a typical stroboscope. A stroboscope consists of a power switch, rpm control dial, range switch, calibration indicator light, calibration screws, combination adjustments, reflector lamp assembly, and other electrical accessories. For information about the functions of the components, consult the operator’s manual. Before you use the stroboscope, be sure to read and follow the manufacturer’s operating instructions. The instrument commonly operates from a 120-volt, 60-Hz, alternating current supply. Any change in current frequency will affect the flashing speed and affect the stroboscope’s accuracy for speed measurements. The stroboscope can be used to measure the speed and to observe the motion of rotating, reciprocating, or vibrating mechanisms. Never leave the stroboscope unattended while it is in use. Since the stroboscope makes a moving object appear to be standing still, someone could be seriously injured by the apparently “stationary” object. TORQUE WRENCH The torque wrench is used to measure an object’s resistance to turning and to provide precise tightening Figure 2-9.—Typical borescope. 2-6