Page VII - 2 
Design Handbook on Animal Research Facilities Using Static Microisolators 
Deflecting vane anemometer: a device that gives instantaneous, direct readings in feet per 
minute, used most often for determining air velocity through supply, return, and exhaust air 
grilles, registers or diffusers. Attachments are used to measure low velocities in an open space or 
at the face of a fume hood. 
Differential pressure gage: an instrument that reads the difference between two pressures 
simultaneously, eliminating the need to take two separate pressures and calculate the difference. 
Electronic Instruments: most of the mechanical analog instruments now have electronic digital 
counterparts. All instruments, analog or digital, should be checked against a sheltered set before 
each balancing project. Pressure measuring instruments should be checked against a standard 
liquid-filled manometer. 
Endotherm: a species that maintains an appreciable difference between body temperature and 
ambient temperature by virtue of internal (metabolic) production of heat. 
FPM (feet per minute): a unit of measurement used for velocity. 
Gage: an instrument for measuring pressure. 
Gage pressure: the pressure that is indicated on the gage. 
Gas chromatography: a chromatographic technique that can be used to separate volatile organic 
compounds. A gas chromatograph consists of a flowing mobile phase, an injection port, a 
separation column containing the stationary phase, and a detector. The organic compounds are 
separated due to differences in their partitioning behavior between the mobile gas phase and the 
stationary phase in the column. 
Homeotherm: species such as mammals and birds that regulate their body temperature 
physiologically. 
Hot wire anemometer: an instrument that measures instantaneous air velocity in feet per minute 
using an electrically heated wire. As air passes over the wire, the wire’s resistance is changed and 
this change is shown as velocity on the instrument's scale. 
Inches of water gage or column: a unit of air pressure using as a reference the pressure exerted 
by a column of water that is one inch high. 
Latent heat: the amount of heat required to convert a quantity of a solid at its melting point into a 
liquid at the same temperature. 
Manometer: an instrument that is the industry standard for reading air pressure. Types of 
