CONSIDERATION OF THE PROCEDURAL ERROR
FOR MEASURING CONTACT SENSOR TEMPERATURE
DURING THERMOPHYSICAL STUDIES
S. V. Reznik,
S. A. Anuchin,
P. V. Prosuntsov,
and A. V. Shulyakovskii
Translated from Novye Ogneupory, No. 3, pp. 29 – 33, March 2009.
Original article submitted September 22, 2008.
The procedural error is described for measuring the temperature of a contact sensor with placement within the
grooves of an experimental specimen made of ceramic material. Mathematical modelling is performed for the
error under specimen one-sided heating conditions. The effect is demonstrated for the error on the result of
processing experimental data by means of mathematical processing of nonstationary nonlinear reverse ther
mal conductivity problems. Recommendations are given for reducing this error.
Keywords: procedural error for measuring temperature (PEMT), contact sensor for measuring temperature,
thermophysical properties (TPP), reverse thermal conductivity problem (RTP), thermocement based on water
In order to plan rocket and space equipment construction
it is necessary to have data about the thermophysical proper-
ties (TPP) of materials over a wide temperature range. Un-
certainty of data about material TPP may lead to an error in
design, going beyond permissible temperature limits and loss
of operating capacity for onboard equipment and instru
Recently there has been widespread use of methods for
determining TPP in which experimental data are processed
by means of software for non-stationary non-linear reverse
thermal conductivity problems (RTP) . In processing ex
perimental data it is particularly important to have accurate
determination of the temperature field for a material speci
men . With use of the most widespread sensors
(thermocouples) the procedural error for temperature mea
surement (PETM) arises due to different optical and
thermophysical properties of the specimen sensor material,
heat flows through electrodes, contact resistance in the zone
of sensor installation, etc.
Publications [3 – 8] have been devoted to a method for
determining the PETM. Before the widespread use of per
sonal computers the error was predominantly determined in
analytical form different methods of placing (fixing) sensors
and temperature regimes. As a result of this complex
dependences were obtained within which there are also such
interconnected values as the rate of change in temperature,
dimensions, thermophysical and optical properties of test
material, and also materials for fastening a sensor and sensor
material itself. Practical use of analytical dependences was
limited due to the considerable number of functions, simpli
fying mathematical description of the actual thermophysical
processes. In practice only a qualitative estimate of this error
was limited, and often it was ignored.
With widespread use of personal computers and develop
ment of programs for modelling heat exchange processes
such as ANSYS, NASTRAN, etc., the situation has changed
fundamentally. Work has appeared within which attempts
have been made to consider PETM on a real time scale.
However, the correctness of methods for fixing heat sensors,
properties of the materials used for mounting them, the na
ture of heat exchange in a complex specimen – temperature
sensor system, have not yet been studied sufficiently.
The aim of this work included determining the dynamic
measurement errors for temperature by contact sensors
(thermocouples) with placement of them in a groove within
the volume of a ceramic specimen and estimating the effect
of these errors on the result of the RTP solution with non-sta
tionary one-sided radiation heating of a specimen.
Refractories and Industrial Ceramics Vol. 50, No. 2, 2009
1083-4877/09/5002-0114 © 2009 Springer Science+Business Media, Inc.
N. É. Bauman MGTU, Moscow, Russia.
FGUP ONPP Tekhnologiya, Obninsk, Kaluzh Region, Russia.
VIAM, Moscow, Russia.