Henssge Nomogram
Definition
A graphical method using rectal temperature, ambient temperature and body weight to estimate PMI within a 95 percent confidence interval, with correction factors for clothing, wind and immersion.
- Confidence level
- 95 percent confidence interval
- Core principle
- Newton's law of cooling
- Key variables
- Rectal temperature, ambient temperature, body weight, plus correction factors
Common questions
What does the Henssge nomogram actually measure?+
The Henssge nomogram estimates the time since death (PMI) using a graphical tool. You plot three known values: the body's rectal temperature, the ambient temperature of the environment, and the deceased's body weight. It gives you a time estimate with a 95 percent confidence interval, meaning the true PMI falls within that range 95 times out of 100.
Can you use the Henssge nomogram in any situation?+
The basic method works from Newton's law of cooling, but real cases need adjustments. The nomogram includes correction factors for clothing, wind, and immersion. Without these adjustments, your estimate could be significantly off. The tool is most reliable when these conditions are documented at the scene.
Why is body weight important for time since death?+
Heavier bodies cool more slowly than lighter ones. Body weight directly affects the rate of heat loss, so the nomogram uses it to calculate how much time has passed based on the difference between rectal and ambient temperature. This is why the dead person's approximate weight is a required input.
Related terms
- Algor Mortis
- Postmortem cooling of the body toward ambient temperature, approximately 1-1.5 degrees Celsius per hour under average conditions. Used alongside other postmortem changes...
- Post-Mortem Interval (PMI)
- The time elapsed between death and discovery or examination of remains. PMI estimation draws on multiple disciplines: soft tissue decomposition stage, insect...
- Rigor Mortis
- The post-mortem stiffening of muscle from ATP depletion and actin-myosin cross-linking. Develops over hours, peaks, and resolves with putrefaction.
- Adipocere
- A waxy, soap-like substance formed by saponification of body fat under anaerobic, wet, cool-to-moderate conditions. Replaces unsaturated fatty acids with saturated palmitic...
- Autopsy
- Systematic external and internal examination of a dead body to find cause, manner and time of death. Ordered under BNSS 2023 Section...
- Cadaveric Spasm
- Instantaneous rigor without a flaccid phase, locking the muscle group active at death (clutched weapon, grass).
- Decomposition
- Autolysis (intracellular enzymes) plus putrefaction (bacterial breakdown). Greenish discoloration starts over the right iliac fossa.
- Livor Mortis
- Postmortem pooling of blood in dependent tissues producing a purple-red discolouration. Becomes fixed at roughly 8-12 hours; discordance between liver position and...
- Livor Mortis (Hypostasis)
- Bluish-purple settling of blood in dependent parts. Begins 30 minutes to 2 hours, fixed by 8 to 12 hours.
- Marbling
- Greenish-black branching pattern over superficial veins from haemoglobin plus H2S. 24 to 48 hour sign.
- Mummification
- Preservation of the body by desiccation rather than liquefaction, occurring when surface evaporation rate exceeds the rate of putrefaction gas production. Common...
- Putrefaction
- Decomposition of tissues by microorganisms, principally anaerobic bacteria from the gastrointestinal tract. Products include hydrogen sulphide, methane, ammonia, and putrescine, which cause...
Explained in these topics
- Time Since Death: PMI, Henssge Nomogram, Tropical CorrectionA graphical method using rectal temperature, ambient temperature and body weight to estimate PMI within a 95 percent confidence interval, with correction facto...
- Post-Mortem Examination, Post-Mortem Changes and Time Since DeathGraphical PMI from rectal temperature, ambient, body weight and a corrective factor. Built on Newton's law of cooling.