BALL BEARING 8M2031 - Caterpillar

All EnginesThe 1P3060 Pyrometer Group is used to measure temperature on a scale of 0° to 1600° F (-18°C to 870°C). An iron-constantan thermocouple is used to generate a millivolt signal that is proportional to temperature. The pyrometer reads the output of the thermocouple and converts it to temperature. Thermocouples are self powered devices, so there is no need for batteries or other external source of power. Use of the pyrometer at ambient temperatures below 0° F (-18° C) will cause incorrect readings.
Use care not to damage the thermocouple lead wire. Sharp bends can cause incorrect readings.
The use of 8B1931, 3B7721 and 4M5317 Adapters will aid in the installation of thermocouples on Caterpillar engines.1P3060 Pyrometer Group Specifications
Components Of The 1P3060 Pyrometer Group
Turn the switch to "0" when the instrument is not in use.
1 The 1P3060 Pyrometer Group consists of box (1), 3H7974 Pyrometer (2), 6H3050 Thermometer (3), two 20639 Adapters (4), and two 8L4439 Thermocouples (5). The storage area of box (1) will hold eight thermocouples. The lead length of thermocouples (5) is 120" (3048); optional 1N7494 Thermocouples with a lead length of 480" (12192) are available from the Parts Department. All of the thermocouples have alloy connecting wires. Pyrometer (2) automatically compensates for the cold end temperature.Use Of The 1P3060 Pyrometer Group
1 Place pyrometer (1) in a location free from excessive vibration. Turn the selector switch to (0) position when the unit is not in use; this dampens needle movement and the unit is less susceptible to damage from vibration or shock. 2 Install thermocouple (2)*. One of the following adapter bushings may be required; 4M5317 - 1/8" × 1/4" NPT; 3B7721 - 1/8" × 3/8" NPT; 8B1931 - 1/8" × 1/2" NPT. The tip of each thermocouple should reach the center of the exhaust pipe or chamber; all tips should have the same spacing from exhaust ports. Refer to the chart on page 15 for probe installation location. *IMPORTANT: The fitting on thermocouple (2) is only initially adjustable. When sealing nut (3) is tightened, the ferrule is imbedded into the metal and cannot be repositioned. 3 With fitting (3) positioned as shown, thermocouple (2) will adapt to most exhaust systems. 4 When tube length-to-thread distance must be shortened, add a 20639 Adapter (4) as shown, or position fitting (3) to the correct length required. If additional 20639 Adapters (4) are needed, they must be drilled out with a .266" Ø (6.8 Ø) drill so they will slide over the .250" Ø (6.4 Ø) thermocouple tube. In situations where thermocouples are used temporarily in a number of engines where probe depth requirements vary, it may be advisable to have several thermocouples (2), each with a fitting (3) for various short length and long length positions. Additional fittings (3) can be made using a 1P3861 Connector, 3D8093 Nut and a 3D8094 Sleeve. 5 Fasten the thermocouple leads to the pyrometer; fasten white wire (+) to white terminal (+) and red wire (-) to red terminal (-). Approximately every