COVER AS 3723925 - Caterpillar

Wire speed meter. On some meters, the letters "rpm" are shown on the clear cover of the dial face. This has no reference to the meter indication, which is shown in "inches per minute" as given on the identification plate on the meter.The meter has a guide with a spring to hold the pickup shaft against the wire. A handle on the meter moves the guide away from the shaft when the meter is to be put on the wire. Both the guide and the shaft have electrical insulation to prevent shock from the current in the electrode wire. The wire speed is shown as a "digital readout" (number indication) on the dial, with an accuracy of plus or minus one inch per minute, and the instrument checks the dial indication at intervals of one second.
To use the meter, push the handle to move the guide away from the pickup shaft, and put the shaft over the wire. Be sure the wire fits into the groove in the guide as the handle is released, and the shaft is in correct alignment with the wire. Wrong alignment of the shaft with the wire, or any movement of the meter along the wire will have an effect on the accuracy of meter indications. To prevent movement, the recommendation is to hold the meter against a stationary support, like the wire feed tube or housing. With the meter in position, push the button (plunger) on the side of the unit to see the speed indication on the dial. For maximum service life, remove the meter immediately after the wire speed has been checked. Constant or long intervals of use cause more wear than necessary to both the guide and the meter.
Wire speed meter in operation.Welding electrode wires used for the addition of hard surfaces on undercarriage components are not all the same. Wires from different sources (factories) can have differences in the density (weight) because of the thickness of the metal sheath (cover), and the core (inside) material. The chart that follows shows the wire feed rates at different current (ampere) settings for some of the available wires.