Chains and Tapes are used to determine distances directly in the field using a variety of techniques that are fundamental components of survey networks. One technique which uses both Chains and Tapes is Chain and Offset.

Measuring distances directly in the field or "chainage" is fairly quick, easy and cheap, and hence is the most common form of distance measurement. Unfortunately, chainage is prone to errors and mistakes. Listed below are several corrections that can be applied to chained distances to minimize systematic errors and to correct for the effects of the physical environment of the measurement process:

• Temperature
• Standardisation
• Catenary (Sag)
• Slope
• Tension
  

Note: The expressions below are used on pages linked to above:

L - true length
l - length as measured
to - temperature of standardization
t - temperature at observation
Dt - (t - to)
M - mass per unit length
to - standard tension
DT - (T - To)
T - Field tension
c - coefficent of linear expansion
E - Young modulus
q - angle of slope in degrees
l' - actual standardized length
DL - correction to length