The ability of a measuring device to maintain its
generally constructed to be as small and light as
calibration under service conditions and over a long
possible to enhance response time. This makes
period of time, is of fundamental interest in tempe-
them vulnerable to deformations that can change
rature control. The IRt/c is rated at less than 0.1°C
the thermoelectric properties. More importantly, the
(0.2°F) repeatability and has no measurable long-
conventional thermocouple must operate at eleva-
term calibration change. This makes it well suited
ted temperature, since it merely measures its own
to reliable temperature control. These attributes
temperature. The metallurgical changes which affect
are inherent in the basic design and construction
thermoelectric properties are a strong function of
of every IRt/c. Repeatability is defined as the
temperature. They are negligible at room tempera-
ability of a measuring device to reproduce its
Quick installation guide
ture, but are of serious concern at high temperature,
calibration under identical conditions. The IRt/c is a
and the IRt/c solves both problems by its design and
solid, hermetically sealed, fully potted system that
does not change mechanically or metallurgically
pre-calibrted models
basic operation. It has a solid fully potted construc-
tion in a mechanically rigid stainless-steel housing,
during service. There are no active electronic com-
and operates at near room temperature conditions.
ponents and no power source to produce the signal,
This essentially eliminates the classical drift pro-
only the thermoelectric effects that produce a
blems of conventional thermocouples. Every IRt/c
thermocouple signal. Long-term accuracy is
is double annealed at temperatures above 100°C
influenced by the same things that influence
(212°F) to ensure long term stability, then tested five
repeatability: mechanical and metallurgical chan-
times prior to packaging. Barring a small percentage
ges, which are known to change the calibration
of failure, the IRt/c has potentially unlimited
of thermocouples over time. Mechanical changes
long-term calibration accuracy.