A gravel pack system includes a tool string having an inner string member, an outer string member, and a passage arranged between the outer string member and the inner string member. The lossy integration is sampled, with a sampling rate and decay rate such that the sample is within a given acceptable error of the maximum value. The retractor includes a base having a body defining a bottom surface and a distal portion, the distal portion defining a distal surface, a first pair of tabs extending from the body that are spaced apart from each other, and a second pair of tabs extending from the body that are spaced apart from each other.