 |
FIGURE 1
The sensor field of view expressed as percent of the input signal coming from the
target at increasing distances from the target. The target was a black body cone, which
had low emissivity aluminum foil around its perimeter. All IRTs accurately measured the
cone temperature when they were less than 0.2 diameters away from the target, but the
fraction of the target viewed decreased as the distance from the target increased.
Click on image for larger view of Figure 1.
|
|
 |
FIGURE 2
TOP GRAPH The errors in the measurement of black body temperature for 4
replicate Exergen IRt/c 0.2 sensors with a narrow field of view. The 4 sensors were
purchased on different dates in 1995 and 1996. Each point represents the mean of 3
replicate readings taken on different days. Each data point was reproducible to within
0.02°C. The five groups of lines represent sensor body temperatures from 15 to 35°C.
BOTTOM GRAPH Measurement error for a single Everest 3000 AL sensor. The four
lines in the bottom graph represent sensor body temperatures from 20 to 35 °C. The mV
output of the 3000 AL transducer was linearized with the fifth order polynomial supplied
by the manufacturer. The error was reproducible on different days and could easily be
corrected in software.
Click on image for larger view of Figure 2.
|
|
 |
FIGURE 3
The dependence of p, h, and k on sensor body temperature. The dependence of each
para-meter on sensor body temperature was described by a polynomial denoted H(sb), P(sb),
and K(sb).
Click on image for larger view of Figure 3.
|
|
 |
FIGURE 4
GENERIC CORRECTION The residual error after correcting for sensor body and
target temperature with one equation for all transducers. The different symbols correspond
to different sensors. This generic correction was adequate to achieve 0.2 °C
accuracy.
CUSTOM CORRECTION The residual error after correcting each of the four
transducers with its own custom correction coefficients. This custom correction was
necessary to achieve 0.1 °C accuracy.
Click on image for larger view of Figure 4.
|
|
 |
FIGURE 5
The variation associated with different lots and different types of thermocouple wire.
Three, type E thermocouples were used to establish a reference thermocouple response. The
type E and type T thermocouples agreed within 0.05°C between 15 and 50°C. The type K
wire read consistently below the E and T wire. All thermocouples agreed within about
0.05°C between 18 and 30°C.
Click on image for larger view of Figure 5.
|
