The DM series comprises two types of precision wirewound multi-turn potentiometers — the DM 106 and DM 107 — designed for applications where the resolution, repeatability, and linearity of a single-turn carbon or cermet track potentiometer are insufficient. By distributing the full resistance range across 10 complete turns of shaft rotation, totalling 3600° ±10° of mechanical travel, the DM series gives the operator a far finer degree of control over the output resistance at any given shaft position than is achievable with a single-turn device. This multi-turn architecture is what fundamentally distinguishes precision wirewound potentiometers from general-purpose rotary types and makes them indispensable in calibration, instrumentation, and analogue computing applications.
The resistance element is formed by winding a precision resistance wire onto a suitable former, a construction that inherently offers superior temperature stability, lower noise, and better long-term resistance drift performance compared to thick film or carbon film alternatives. The rated resistance values available span from 220Ω up to 47kΩ across a selected set of preferred values: 220Ω, 470Ω, 1kΩ, 2.2kΩ, 4.7kΩ, 10kΩ, 22kΩ, and 47kΩ, covering the impedance range most commonly required in precision analogue signal and reference circuits.
Resistance tolerance is available in three grades — ±2.5%, ±5%, and ±10% — allowing specifiers to select the level of initial accuracy appropriate to their application and cost requirements. More critically for precision use, the resistance linearity — the maximum deviation of the actual output from the ideal linear law across the full travel — is offered in five grades: ±0.05%, ±0.1%, ±0.15%, ±0.25%, and ±0.5% of rated resistance. The tightest linearity grade of ±0.05% Rn represents an exceptionally accurate transfer characteristic, making the DM series suitable as a primary precision element in analogue computing, bridge measurement, and high-accuracy feedback circuits where positional accuracy must translate reliably into a known resistance output.
The power rating of 0.75W and voltage limit of 100V AC reflect the DM’s role as a precision signal-level component rather than a power-handling device. The climatic category of 25/085/21 defines operation from +25°C to +85°C with humidity endurance qualification, appropriate for laboratory, instrumentation, and indoor industrial environments. Both the DM 106 and DM 107 are supplied in bulk plastic bag and carton box packaging.
