Voltage dividers and voltage references provide highly-accurate reference voltages for calibration and testing purposes. Voltage dividers produce an output voltage (V_out) that is proportional to an input voltage (V_in). They consist of a series of fixed resistors (R₁ and R₂) that function as a highly accurate, variable potentiometer. Kelvin-Varley devices, a type of voltage divider, use a bridge circuit with two standard-value resistors. The ratio of the resistance value determines the voltage or current ratio. Operating specifications for voltage dividers and voltage references include temperature coefficient, operating temperature, and stability. Voltage and current specifications for voltage dividers and voltage references include input voltage range, output voltage range, voltage accuracy, voltage resolution per step, current range, current accuracy, and current resolution per step. 

Voltage dividers and voltage references include voltage standards, decades, decade boxes and substituters. Voltage standards provide highly accurate, standard values of resistance, capacitance, inductance, or voltage for calibration and testing. Voltage standards usually consist of a single, fixed value component (e.g., resistor), or several components that are not in the same circuit. Products with more than one component (e.g., several fixed-value resistors) have multiple posts or a rotary switch to selected different resistance values. Like voltage standards, decade boxes (decades, decade substituters) also provide highly accurate and digitally variable standard values of resistance, capacitance and inductance. Decade boxes usually consist of several resistors within the same circuit. With these voltage dividers and voltage references, the standard value of resistance is selected by varying the number of resistors in the series of parallel circuit.  

Traceability and Features

Voltage dividers and voltage references differ in terms of traceability and features Often, products such as voltage standards can be traced to the National Institute of Technology Standards (NIST), or some other national laboratory. Transfer, primary, or laboratory-grade standards are used to compare or transfer the accuracies from NIST to working standards, sources, simulators and calibrators for precise calibration. Working standards, robust or rugged units for production or in-line testing or calibration, can then be used. In terms of features, some voltage dividers and voltage references have low values of zero, offset or residual impedance resistance, inductance or capacitance. Others can provide a precise and continuously variable value with a variable capacitor, digital potentiometer, or bridge. Voltage dividers and voltage references such as thermocouple simulators can be used to output a precise voltage to simulate the millivolt potential of thermocouple junctions.