Distributions of RV differences between two epochs of the same WDs, scaled down by , along with Gaussian fits to the distributions (dashed red lines), for pairs of measurements having pair-averaged calculated RV fitting errors of 5–20 km s⁻¹ (left), 20–35 km s⁻¹ (centre), and 35– 50 km s⁻¹ (right). The distributions appear Gaussian with a σ close to the expected value. This alignment indicates the reliability of the calculated RV errors.