Techkor Instrumentation provides free
technical support for one full year after the purchase of a product. In
addition Techkor stocks a library of technical articles to help answer many
of the most common questions about signal conditioning.
Shown below are introductory paragraphs or
summaries of some of our most requested articles.
An Intelligent Wireless Data Gathering System for Condition Based
Maintenance
An Introduction to Vibration
Measurement
An Introduction to Linear Regression Analysis
An Introduction to the Resistive Strain Gage
An Introduction to the Linear Variable Differential Transducer
An Introduction to the Thermocouple
An Intelligent Wireless Data Gathering System for Condition Based
Maintenance
Advances in wireless technology, battery
chemistry, and miniaturization have made large-scale wireless CBM data
gathering systems practical. Wireless sensing no longer needs to be
relegated to locations where access is difficult or cabling is not
practical. Wireless CBM data gathering can be cost effectively implemented
in extensive applications that were historically handled by route running.
To receive the full benefit of an
industrial condition based maintenance program, it is necessary to have
up-to-date equipment condition. When compared with route running, return on
investment can be significantly higher for data gathering systems that
provide machine condition four or more times a day. Most modern
manufacturing facilities are not able to fully implement surveillance
systems due to the high capital costs, installation difficulties, and the
overall complexity of the system. Monthly or weekly route running remains
the most common implementation of condition based maintenance (CBM).
The condition based maintenance practice
of surveillance monitoring would benefit significantly from intelligent,
inexpensive, wireless sensors. The result would be a lower cost surveillance
program, easier sensor node placement, simpler data gathering, increased
safety, and seamless reconfiguration or expansion of sensor nodes. In short,
surveillance programs would be easier to apply to a wider variety of
applications.
This publication will detail the major
issues surrounding the development of a wireless surveillance system for
practical application in the factory environment. A wireless surveillance
system must address the reliability of the wireless communication network,
cost, battery life, ease of configuration, miniaturization and intelligence,
all while retaining the accuracy and bandwidth of traditional sensors. A
careful balance is necessary...
To request a hard copy of a technical brief call Techkor at (717) 939-2300, or
download the PDF file
here.
An Introduction to
Vibration Measurement
Vibration testing and measurement are very important in
the development, testing and monitoring of most engineered products. Whether
you are involved in meeting Department of Defense vibration test standards
(MIL-STD-810E , Method 514.4) or performing a simple shaker test the
fundamentals are the same. Vibration measurements are commonly performed
with accelerometers due to their high accuracy, wide bandwidth, small size,
light weight and ease of use. In the simplest terms, an accelerometer is a
device...
To request a hard copy of a technical brief call Techkor
at (717) 939-2300, or download
the PDF file
here.
An Introduction to Linear Regression Analysis
Linear regression analysis is a method of
fitting a linear equation through a set of calibration data. Commonly
referred to as curve fitting, regression analysis is used to find
calibration equations for many instrumentation system. Although a simple
calibration could be performed with only two points defining a straight
line, regression analysis uses an overdetermined set of data to improve the
accuracy of the calibration line. With the MEPTS-9000™ system, a highly
accurate calibration equation can be obtained through linear regression
analysis. Although it is not necessary in most cases, the accuracy of most
MEPTS-9000™ calibrations can be improved through the use of linear
regression analysis...
To request a hard copy of a technical brief call Techkor
at (717) 939-2300, or download
the PDF file
here.
An Introduction to the Resistive Strain Gage
A strain gage is a thin metal foil that
changes resistance with applied strain. Strain gages are the preferred
choice in stress analysis due to their small size and relatively low cost.
An entire test specimen can be gaged for multiple point stress analysis at a
very low cost. Strain gages can measure strain levels from a few microstrain
(µ) to over 100,000 microstrain. When used in conjunction with a precision
signal conditioner, accurate strain measurements are possible. The
introductory user is cautioned to be aware that there are many pitfalls
involved with strain gage measurements. Careful attention to the various
error sources will assure accurate measurements. This technical brief will
address basic strain gage theory and some of the more common problems
associated with strain gage measurements...
To request a hard copy of a technical brief call Techkor
at (717) 939-2300, or download
the PDF file
here.
An Introduction to the Linear Variable Differential Transducer
A Linear Variable Differential Transducer
(LVDT) is an electromechanical device that produces an output proportional
to displacement. LVDT's offer many distinct advantages over other
displacement measurement devices including: frictionless movement, infinite
resolution, null repeatability, temperature stability, and environmental
ruggedness. LVDT's can measure displacements from a few microns to several
feet in a wide variety of environments. An LVDT operates on the principal of
magnetic coupling between a primary and two secondary windings. The primary
coil is typically energized with a 2-5 Volt sine wave with frequencies
between 2-10 kHz. The primary winding produces a magnetic field which passes
through the two secondary windings. A magnetically permeable metal core (Ni-Ir)
slides through the center of the coils and provides an efficient path for
the magnetic flux. The amount of Voltage induced in the secondary windings
varies with the core's position...
To request a hard copy of a technical brief call Techkor
at (717) 939-2300, or download
the PDF file
here.
An Introduction to the Thermocouple
Thermocouple effects were originally
observed by the Estonian physician Thomas Seebeck. While experimenting with
a junction of bismuth and copper, he accidentally observed a magnetic
disturbance on a nearby compass. Seebeck experimented with different metal
combinations at various temperatures, noting relative magnetic field
strengths. His work was published as "thermo-magnetism" in a 1822 paper, "Magnetische
Polarisation der Metalle und Erze durch Temperatur-Differenze." Further
investigations have shown the Seebeck Effect to be purely electrical in
nature. The electrical effect is highly repeatable and naturally occurring
making it useful in temperature measurement. Potential problems with
thermocouples include: low output voltage, low sensitivity, non-linearity,
and electrical connections. Typical thermocouple sensitivities are around 50
µV/ C. Extensive amplification is necessary to bring thermocouple voltages
up to Volt levels. The non-linearities inherent to thermocouples can be
several percent over full scale ranges. Careful attention must be paid to
thermocouple calibrations to account for this nonlinearity. Connections in
thermocouple systems must be made with great care. Unintended thermocouple
effects from a copper and solder junction creates a 3 µV/ C thermocouple...
To request a hard copy of a technical brief call Techkor
at (717) 939-2300, or download
the PDF file
here.
