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Sources of errors in chaining/taping
Short answer
Incorrect tape length, temperature, sag, slope, poor alignment cause cumulative errors (measured too long/short). Marking, reading, plumbing variations are compensating (random). Blunders like miscounting are mistakes.
Tabulate the various sources of errors occurring in chaining/taping with their directions (cumulative or compensating).
Errors are classed as cumulative (systematic), which keep the same sign and add up with the number of tape lengths, and compensating (accidental), which are equally likely to be positive or negative and partly cancel out.
| Source of error | Cause | Effect on measured length | Type |
|---|---|---|---|
| Incorrect length of tape | Tape too long or too short compared with the standard | Too long tape: measured too short (). Too short tape: measured too long () | Cumulative |
| Temperature variation | Field temperature differs from standard | or as temperature is lower or higher | Cumulative (compensating over a day if it varies) |
| Pull (tension) variation | Pull more or less than standard | Cumulative if pull is always more/less, otherwise compensating | |
| Sag | Tape hangs between supports | Measured too long () | Cumulative |
| Slope (not horizontal) | Tape held along the slope | Measured too long () | Cumulative |
| Poor alignment | Tape not in line between ends | Measured too long () | Cumulative |
| Bad straightening | Kinks, curves in tape | Measured too long () | Cumulative |
| Marking tape ends | Arrow placed slightly ahead or behind | Compensating | |
| Reading and plumbing | Wrong estimate of fractions, plumb bob swinging | Compensating | |
| Variation in pull in a short range | Hand tension changes | Compensating | |
| Wrong booking and miscounting | Mistake, not error | Large | Blunder (mistake) |
Cumulative errors are corrected by calculation; compensating errors are reduced by repeated measurements.
✓ Answer checked by Claude Opus 5.5 (high effort)
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