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A carbon composition resistor uses a bulk mixture of carbon and insulating binder. The conducting network sets its electrical resistance. Its compact geometry has little winding inductance, but composition and contact fluctuations can cause excess electronic noise and changes of electrical resistance with temperature and aging. It differs from a carbon-film resistor.

For independent contributions the parametrization meansThe stochastic coefficient $A$ includes fluctuations in the sampled shower fraction, the finite number of signal quanta, and intrinsic shower fluctuations. A number of detected quanta proportional to $E$ has fluctuations proportional to $\sqrt{E}$, giving relative resolution proportional to $E^{-1/2}$. The noise coefficient $B$ describes an approximately fixed energy-equivalent readout uncertainty, including electronic noise and, for specified running conditions, Pile-up contributions. The constant term $C$ represents residual fractional nonuniformity, calibration and response variations, imperfect correction for inactive material, and leakage effects over the fitted range. The simple three-term model is an approximation; leakage and Pile-up need not follow these powers exactly.

A homogeneous calorimeter uses the showering material itself as the active medium, for example a scintillating crystal. It removes the absorber-versus-active sampling fluctuation and can have a much smaller stochastic term, but it does not eliminate signal statistics or intrinsic shower fluctuations. Its noise and constant terms are not automatically smaller: they depend on light collection, calibration, temperature, radiation damage, electronics and geometry. Homogeneous detectors can offer excellent energy resolution and compact construction, but large crystal volumes can be costly and fine longitudinal segmentation difficult. Sampling detectors often provide economical large coverage and flexible segmentation with robust absorbers, at the cost of sampling fluctuations and inactive material. If energy is expressed in GeV, $A$ has units ${\mathrm{GeV}}^{1/2}$, $B$ has units GeV and $C$ is dimensionless.