FLIR T Series User Manual

part. At a certain height there is a neutral zone where the pressures on the inside and
outside are the same, see the figure on page 164. This differential pressure may be
described by the relationship:
Air pressure differential within the structure in PaΔp
9.81 m/s
2
g
Air density in kg/m
3
ρ
u
Thermodynamic air temperature outdoors in KT
u
Thermodynamic air temperature indoors in KT
i
Distance from the neutral zone in metersh
If ρ
u
= 1.29 kg/m
3
(density of air at a temperature of 273 K and ≈100 kPa), this pro-
duces:
With a difference of +25°C (+77°F) between the ambient internal and external tem-
peratures, the result is a differential pressure difference within the structure of about
1 Pa/m difference in height (= 3.28 Pa/ft.).
Publ. No. 1558792 Rev. a460 – ENGLISH (EN) – July 1, 2010 163
27 – Introduction to building thermography

FLIR T Series Specifications

General

Brand	FLIR
Model	T Series
Category	Thermal cameras
Language	English