Raman Tools
Repeatability and measurement uncertainty (RSD)
What is the scatter of your replicates? Paste a series of results (intensities, concentrations, or whatever you measure), and we will calculate the mean, standard deviation, relative standard deviation (RSD in %), and the 95% confidence interval — essential figures for assessing method repeatability and quality control.
Replicates
One value per line (or separated by commas/spaces). Minimum of 2 measurements.
Formulas and assumptions
Mean x̄ = Σxᵢ / n
SD = √( Σ(xᵢ − x̄)² / (n − 1) ) (sample standard deviation)
RSD [%] = 100 · SD / x̄
SEM = SD / √n · CI₉₅ = x̄ ± t · SEM
Standard deviation calculated using the sample method (divisor n−1). The confidence interval uses the t-distribution (df = n−1), making it reliable even for small series. RSD is meaningful for positive quantities on a ratio scale — it can be misleading for values near zero.
This is the statistics of your data — it does not replace full method validation (intermediate precision, inter-day reproducibility, etc.).
Have a sample you don’t want to guess about?
We conduct feasibility studies even on the most challenging samples — on your material, at your site. Leave your contact, and we will review your case and tell you directly whether Spectrally can measure it.
