The Fluke Model 2100A is a digital, thermocouple thermometer, employing the dual-slope integration technique, and capable of making precise temperature measurements in either degrees Fahrenheit (°F) or degrees Celsius (°C). The instrument is fully guarded and features a fully isolated input. 1-3. The 2100A has a five-digit readout (plus sign) capable of indicating up to ±3999.9 degrees. However, the range of the instrument is determined by the type of thermocouple used. The instrument can be ordered, configured to use any of the following types: J, K, T, E, R and S. Table 1-1 shows the temperature ranges for each of these types. Resolution of the instrument is 0.1 degree, except in instruments using a type R or a type S thermocouple and indicating in °F, when resolution is 0.2 degrees. The readout features 0.5 inch characters, fixed decimal point, and leading-zero suppression for the two most significant digits. 1-4. The 2100A is available in three basic models: the 2100A—03, the 2100A-06, and the 2100A-10. The 2100A--03 is a single-point instrument (one input); the 2100A-10 is a multi-point instrument (10 inputs). Both of these models are tailored at the factory to use only one specific type of thermocouple. Once tailored, the 2100A— 03 and 2100A—10 are limited to that one type, but can be converted to any one of the other five at any time, by means of a conversion kit. 1-5. The 2100A—06 is a multi-type instrument. It is tailored to accept inputs from any of the six different types of thermocouple, but only one type at any given time. (The 2100A—06 is not a multi-point instrument). In effect, the 2100A—06 is a 2100A—03 that can be rapidly converted to accept different thermocouples, by means of integral selector switches, rather than conversion kits. For valid indications from a 2100A—06, the selector switch depressed must correspond to the type of thermocouple being used. In addition, the 2100A—06 can accept linearized voltage inputs on either of two selectable mV ranges directly from other transducers, such as bridge-connected strain gauges. Table 1-2 is a summary of the differences between the three basic models of the 2100A.