This is not a simple potentiometer or variable resistor. The CEM R-100 is a laboratory-class decade resistance box designed to simulate high-accuracy resistances in seconds. Its seven rotary switches — seven decades — let you create any resistance value you need between 1 Ω and 11,111,110 Ω precisely, in 1 Ω steps. That makes it an indispensable reference for calibration laboratories, service departments and electronic design engineers.
A decade box lets the user select and combine a series of precision resistors arranged in powers of ten — units, tens, hundreds, thousands — through rotary switches, producing a very specific total resistance.
The result? The instrument's terminals now present a stable, dependable resistance of exactly 47,521 Ω, within ±1% tolerance.
This capability is decisive in two areas above all: calibration and prototyping.
When a multimeter or ohmmeter reads "100.0 Ω", how certain are you that the value really is 100.0 Ω? Test and measuring instruments drift over time through environmental factors, use or minor knocks. Calibration is the process of detecting and correcting that drift.
Carried out periodically, this verification keeps your measurements accurate and dependable. For any service department or laboratory that must comply with ISO standards, or that takes precise measurements, it is a critical process.
Electronic circuit design is a process of trial and error. When designing a sensor circuit, a filter or an op-amp stage, theoretical calculations do not always hold in practice, and you need an answer to questions like: if the 10 kΩ resistor at this point in the circuit were 12 kΩ, how would the output change?
The CEM R-100 does not simply offer a wide range — it does so with reliability and ease of use.
