Ohm-Labs Custom Precision Wire-Wound Resistors

For applications requiring exceptional accuracy and reliability, Ohm-Labs offers a range of custom-made wirewound resistors. These components are designed for customers who demand the highest standards in measurement stability, temperature behaviour and service life. Ohm-Labs manufactures these resistors exclusively to special order, with a range from 0.01 Ω to 10 MΩ. Thanks to the acquisition of production and material lines from Leeds & Northrup, Honeywell and Julie Research Labs, we can continue to supply original designs with the corresponding materials and specifications. OEM part numbers from these brands can be supplied directly for a quotation.

Various models and types

The series consists of several models, each optimised for specific applications:

R-type: Epoxy-encapsulated resistors, suitable for standard applications with 2- or 4-wire connections.
H-type: Hermetically sealed, oil-filled resistors for maximum stability and protection against environmental influences.
T-type: Radial “Top Hat” resistors with compact mounting form, ideal for applications with limited space.

Within each type, different sizes are available, varying in diameter and length. The choice between 2-wire and 4-wire construction depends on the desired accuracy; 4-wire is recommended for resistors below 10 ohms.

Specifications and customisation

Customers can specify their desired accuracy, from 0.1% to as low as 0.001%, with corresponding temperature coefficients (TCR) of less than 20 ppm/°C to even below 1 ppm/°C. The resistors are supplied with solid lead wires (22 to 18 AWG), and for higher power ratings, an -HK version with heat sink is available. For applications where multiple resistors must be precisely matched, such as ratio matching, Ohm-Labs also offers custom-matched sets.

Accuracy and TCR options