In volumetric calculations what device when used on an isopach map can mechanically measure the area inside circumscribed lines?

In volumetric calculations what device when used on an isopach map can mechanically measure the area inside circumscribed lines?

• A. Planimeter
• B. Caliper
• C. Ruler
• D. Perimeter Gauge

Answer: (A)

When you’re doing volumetric calculations from an isopach map, you first need the area enclosed by the circumscribed lines, because volume is this area times the thickness (or the integral of thickness over that area). A planimeter is the device designed to mechanically determine the area inside a boundary on a map by tracing along the edge. As you trace, it integrates the shape and provides the enclosed area, which you then multiply by the thickness to get volume. The other tools don’t serve this purpose: a caliper measures thickness or small linear dimensions, a ruler gives straight-line distances, and a perimeter gauge notes the length of a boundary rather than the area it encloses.

When you’re doing volumetric calculations from an isopach map, you first need the area enclosed by the circumscribed lines, because volume is this area times the thickness (or the integral of thickness over that area). A planimeter is the device designed to mechanically determine the area inside a boundary on a map by tracing along the edge. As you trace, it integrates the shape and provides the enclosed area, which you then multiply by the thickness to get volume.

The other tools don’t serve this purpose: a caliper measures thickness or small linear dimensions, a ruler gives straight-line distances, and a perimeter gauge notes the length of a boundary rather than the area it encloses.