Hair can be measured in a variety of ways, depending on the purpose of the measurement.
Measuring Hair Thickness:
- Micrometer Caliper: This tool physically and mechanically measures the diameter of a single hair strand.
- Phototrichogram: This method uses imaging to measure hair thickness.
Measuring Hair Length:
- Ruler or Tape Measure: For precise measurement, a ruler or tape measure can be used to determine the length of a strand of hair from root to tip.
- Body Part Measurements: This method uses body parts as reference points for estimating hair length. For example, hair that reaches the shoulders could be described as "shoulder-length."
- LHC Profile Settings: Online communities dedicated to long hair often use specific standards for measuring hair length. These may involve measuring the hair from the front hairline, over the head, and down the back.
Measuring Hair for Braiding or Extensions:
- Length without the Bend: Braiding hair and hair extensions are typically measured without the bend at the end of the strand.
- Knotless/Feed-in Braids: For these types of braids, the exact measurement is less critical, as the hair is gradually added to the braid.
Measuring Hair for Scientific Research:
- Cortisol in Hair: Hair analysis can be used to measure cortisol levels, which can serve as a retrospective biomarker for increased cortisol production.
- Testosterone-like Immunoreactivity: Scientists can measure testosterone-like immunoreactivity in hair using radioimmunoassays.
- Hair Follicle Drug Tests: These tests analyze a small hair sample to detect drug use, providing a history of drug consumption over weeks or even months.
