# What does L mean in Uncertainty Measurement Result U(E)=0.08+1.2L ;k=2? [closed]

I'm calculating the combined measurement uncertainty u(c) of a measurement for a length displacement sensor. Amongst other factors, one individual uncertainty affecting the error of measurement is the uncertainty of the gage block I'm using. In the calibration certificate of the gage block the uncertainty of measurement is expressed as:

$U(E)=0.08\ \mathrm{µm}+1.2\ \mathrm{L}$

With the coverage factor $k=2$.

The nominal thickness of the gage block is 10 mm and usually uncertainty is expressed as just ±0.08 µm. In this case, what does $L$ stand for?

• Can you add references to the above equation? – Mahendra Gunawardena Feb 21 '16 at 2:02

$$\text{Table 2.3} \\ \begin{array}{cc} \text{Grade} & \text{Deviation from Nominal} \unicode{0x000A} \text{Length (µm)} \\ 00 & (0.05 + 0.0001L) \\ 0 & (0.10 + 0.0002L) \\ 1 & (0.20 + 0.0004L) \\ 2 & (0.40 + 0.0008L) \\ \end{array}$$