Nutrient limitation and stoichiometry of carnivorous plants

Micro-bomb Calorimetry

by Jim Karagatzides, Harvard Forest

Calibration - Set-up - List of Materials - LoggerNet Instructions and Datalogger files

Description

The micro-bomb calorimetric method described herein was provided by KL Griffin. In this setup, a thermocouple is inserted directly into the bomb chamber and a datalogger used for rapid (<5 seconds) measurement of heat of combustion (maximum temperature; Figure 1). As with othe
r bomb calorimeters, the instrument is calibrated against a standard of known calorific content (e.g., benzoic acid). Most analysts run each sample in duplicate and undertake a triplicate analysis if the difference exceeds 2%.

Click here for an exploded view. 

Useful Tips

• Clean parts with ethanol being careful of leaving behind fibers if you use any cotton swabs.
• Store wire in ethanol and cut wire pieces in advance.
• Check the system for leaks after putting the bomb together with soapy water (or Snoop); the best approach at first may be to immerse the whole unit in water.
• Use gloves and do not touch anything with your fingers as oils on your hands will contaminate the sample.
• A Sonicare cleaning system (usually used for jewelry) may remove built up ash.
• Additional standard reference material for calibration is available (NIST 203_1.pdf)