High-accuracy digital multimeters manufacture might need a resistor component for a new series of 8.5- and 7.5-digit units. To achieve necessary 8.5-digit accuracy, the specified resistor needed to offer extremely low TCR, high-precision, repeatability, low thermal EMF, low noise, long-term stability and minimal harmonic distortion. As the multimeter was based on an analog circuit design, the resistor needed to have minimal drift from initial values when operating above room temperatures. Microhm NTP series is applicable to this application.
Diode Laser Current Drivers
In another example, low-cost and easy-to-use diode lasers are a virtual measurement staple in experimental atomic physics. For a diode laser to maintain its frequency, output power, current and temperature, careful regulation of parameters is required.
To generate a suitably stable laser stream, the current sense resistor needed to be resistant to both internal and external temperature drifts, have a high-power rating, and a low thermal EMF. The most critical element of the current driver is the sub-circuit, responsible for current regulation since laser stability must not exceed overall sense resistor stability. In this application, the use of traditional commercial current controllers was too cost-prohibitive. The viable resistor solution therefore needed to be both low-cost and high-precision. Microhm's
high-precision metal foil resistor with a low TCR are ideal solution.
Metrology Institute might need a high-precision resistor solution. To serve as an adequate secondary reference standard, a cost-effective, high-precision resistor, the values of which needed to closely match those of the primary standard, yet offer a well-defined four-terminal configuration, low noise, low TCR and no RH effect, along with excellent long-term stability. Microhm also provide resistors for this application.
