Temperature Sensors
United Electric Controls is a major manufacturer of
thermocouple, RTD, thermistor and other types of temperature sensor assemblies.
ISO 9001 certified and a leading practitioner of Lean Manufacturing methods, we
focus on building high-quality, high-reliability products for the industrial
market. Our expertise covers a wide variety of applications, from lab equipment
to road-making equipment, from the blast furnace to the blast chiller, and
everything in between.
We design, engineer
and manufacture:
• Thermocouples
• RTDs both wire wound and thin
film
• Thermistors
• Integrated Circuit temperature
sensors
• We also have Temperature Sensor
Accessories available
All of our products
are known for their consistent high reliability, cost effectiveness and
durability. We are continually examining and improving our engineering,
production and service operations to meet constantly changing customer
requirements. Our ISO 9001 certification is objective proof of our company wide
commitment to quality.
UE Temperature Sensor
Group
UE has assembled a
talented group of Temperature Sensor experts to form our Sensor Group at our
Headquarters in Watertown, MA. This organization is specifically formed to
serve our wide spectrum of customers. We have experienced professionals
dedicated to producing the best temperature sensors for a wide variety of
applications. This group consists of experts with extensive Temperature Sensor
experience in:
• Sales •
Supplier Development
• Design • Manufacturing and Quality Assurance
• Engineering • Customer Service
• Marketing
UE
Temperature Sensor Customers
At UE we manufacture
all types of Temperature Sensors and have customers purchasing both custom
designed and standard catalog products.
OEM Sensors
United Electric
Controls Co. excels in supplying today's manufacturers with temperature sensors
that meet their needs. We can help you develop, and then manufacture the sensor
that works with your product. UE brings many strengths to the OEM customer,
including:
• Sales personnel
located around the world so they can be available to serve customers whenever
and wherever they need assistance.
• Engineering Expertise to work with your engineers to
develop the right design.
• Highly efficient manufacturing processes are designed to
build your sensor economically and reliably.
• Quick Response to Orders - UE can deliver your parts when
you need them.
We manufacture
temperature sensors for many different types of customers' applications. Some
of our customers use UE Temperature Sensors in:
• Scientific instruments - Storage and measurement
• Food Equipment - Cooking, Storing and Cleanup
• Medical equipment - Sterilizing, biological storage
• Jet fighters, helicopters
• Energy - Turbines, generators and fuel cells
Temperature
Sensor Styles
Temperature Sensors at UE are built in a broad spectrum of
styles. They are:
Leadwire - Standard thermocouples with fiberglass, Teflon®
or PVC insulation available with a variety of protective coverings including
Teflon® sleeves
Terminal Heads -Configurations including Enclosure Type 4 and 7
heads; with or without NUN (nipple-union-nipple) connections.
Process Mount - Double and single sided process mount styles
and single sided instrument mounts
Plugs - Standard and mini male plugs with and without leadwires.
Surface Mount - A variety of mounting options including washer
styles, mounting lugs and weld pads; with fiberglass or Teflon® insulation
Which Sensor Should I
Use?
When choosing which temperature sensor to use there are many
things to consider. One very important decision is selecting the type of sensor
that best fits your requirement. Below is a description of the types of
Temperature Sensors that United Electric Controls Co. designs, engineers and
manufactures. Each technology has advantages and limitations.
Thermocouples
Thermocouples can measure temperatures over wide ranges,
inexpensively. They are very rugged, but they are not as accurate as RTDs and
thermistors.
A thermocouple is basically two strips of wires of
dissimilar metals. These metal wires are joined at one end and the voltage is
measured at the other end. Changes in the temperature at the juncture induce a
change in electromotive force (emf) at the other end. As the temperature goes
up, this output emf of the thermocouple rises, though not necessarily linearly.
Here is a summary of some of the advantages and
disadvantages of thermocouples:
Advantages Disadvantages
Self Powered Non Linear
Simple Low Voltage
Rugged Reference Required
Inexpensive Least Stable
Wide Variety Least Sensitive
Wide Temperature Range
Thermocouple
Types
There are many
different types of thermocouples. They are made of different types of wire and
have very different properties, making one type better for a specific
application than another. Below are descriptions of the types of thermocouples
that United Electric Controls Co. makes.
Type J
The Iron - Constantan
"J" curve thermocouple is the most widely used thermocouple; it is
versatile and has a relatively low cost. It has a positive Iron wire and a
negative Constantan wire and is recommended for reducing atmospheres. The
operating range for this alloy combination is from 0° to 750°C (32° to 1380° F)
for the largest wire sizes. Smaller size wire should operate in correspondingly
lower temperatures.
Type T
The Copper -
Constantan "T" curve thermocouple, with a positive Copper wire and a
negative Constantan wire, is recommended for use in mildly oxidizing and
reducing atmospheres at temperatures from 0° to 350° C (32° to 660 °F). They
are suitable for applications where moisture is present. This alloy is
recommended for low temperature work since the homogeneity of the component
wires can be maintained better than with other base metal wires. Therefore,
errors due to inhomogeneity of wires in zones of temperature gradients are
greatly reduced.
Type K
The Chromel™ -
Alumel™ "K" curve thermocouple is often used at high temperatures. It
has a positive Chromel™ wire and a negative Alumel™ wire and is recommended for
use in clean oxidizing atmospheres. The operating range for this alloy is from 0°
to 1250° C (32° to 2280° F) for the largest wire sizes. Smaller size wire
should operate in correspondingly lower temperatures.
Type E
The Chromel ™ -
Constantan "E" curve thermocouple has the highest emf of all standard
thermocouples. It has a positive Chromel ™ wire and a negative Constantan wire
and is recommended for use in oxidizing, inert or dry reducing atmospheres or
for short periods of time in a vacuum. These elements must be protected from
sulfurous and marginally oxidizing atmospheres. Type E thermocouples can be
used for temperatures from 0° to 900° C (32° to 1650° F).
Thermocouple
Insulation Types
United Electric
Thermocouples are available in three versions:
GP - General Purpose thermocouples that are comprised of a
pair of thermocouple wires inside a tube. These are used to measure
temperatures of 260° C (500° F) or less.
MI - For
higher temperature applications, a Mineral Insulation can be added in the tube.
For UE MI thermocouples compressed magnesium oxide is added inside the tube.
These are used to measure temperatures of 260° C (500° F) and higher.
BTC - Beaded thermocouples are mainly used in furnace
applications.
RTD's or
Resistance Temperature Detectors
RTD's are stable and
have a fairly wide temperature range, but are not as rugged and inexpensive as
thermocouples. Since they require the use of electric current to make
measurements, RTD's are subject to inaccuracies from self-heating.
An RTD capitalizes on
the fact that the electrical resistance of a material changes as its
temperature changes. RTD's rely on the resistance change in a metal. The
resistance will rise more or less linearly with temperature.
Traditionally, RTD's
use a length of conductor (platinum, nickel iron or copper) wound around an
insulator. Newer styles use a thin film of the conductor deposited on a ceramic
substrate.
RTD's are used to
measure temperatures from -196° to 482° C (-320° to 900° F)
Here is a summary of
some of the advantages and disadvantages of RTDs:
Advantages Disadvantages
Most Stable Expensive
Most Accurate
Current Source Required
More Linear than Thermocouple Small delta R
Low Absolute resistance
Less Rugged that Thermocouples
Thermistors
Thermistors tend to
be more accurate than RTD's and thermocouples, but they have a much more
limited temperature range because of their marked non-linearity.
A Thermistor
capitalizes on the fact that the electrical resistance of a material changes as
its temperature changes. Thermistors rely on the resistance change in a ceramic
semiconductor, with the resistance dropping non-linearly with a temperature
rise.
Thermistors can be a low cost solution to temperature
measurement. They tend to have large signal outputs and their small size
permits fast response to temperature changes. UE Thermistors are used to
measure temperatures from -45° to 260° C (-50° to 500° F)
Here is a summary of
some of the advantages and disadvantages of thermistors:
Advantages Disadvantages
High Output Non
Linear
Fast Limited Temperature Range
Two-wire ohms measurement Fragile
Current Source Required
Self-heating
IC Sensors
The newest type of
temperature sensor on the market is the integrated circuit (IC) temperature
transducer. IC sensors can be designed to produce either voltage or current
output and are extremely linear.
IC sensors are a very
effective way to produce an analog voltage proportional to temperature. They
have a limited temperature range and are used to measure temperatures from -45°
to 150° C (-50° to 300° F)
Here is a summary of
some of the advantages and disadvantages of IC Sensors:
Advantages Disadvantages
Most Linear
Temperatures limited to 150 degrees C
Highest Output Power
Supply Required
Inexpensive Slow
Limited Configurations
Self-heating