The Temperature Sensor Specialists

Constantly improving temperature measurement.

logo

Category Archives: Technical Information

Mineral Insulated Resistance Thermometer

Mineral Insulated Resistance thermometers are a very common form of temperature sensor. It surprises me how often design engineers are not familiar with the product. They may be called Metal clad, MIMS, or simply MI.

 

Basic design of Mineral Insulated Sensors

 

The basic Mineral Insulated Resistance Thermometer design has a sensor and conductors inside a metal tube. Insulation is provided by tightly packed Magnesium Oxide powder. The assembly is robust and ductile. Smaller diameters can be easily bent by hand allowing fairly simple installation through very difficult routes. Diameter 6.0 mm and above are more difficult to bend, but can still be routed as required.… Read more

Temperature Sensor Design Consultancy

Good temperature sensor design can be a demanding task. Peak Sensors can undertake contracts to provide advice on sensor design, independent to our own ability to subsequently make the final probe.

 

Good temperature Sensor design involves consideration of:

 

Accuracy requirement

Cost

Process connection demands

Temperature range

Physical size constraint

Probe environment

Compliance requirements

Signal processing and output

 

Other than Infrared devices, Temperature Sensors need to be in thermal contact with the target process medium. Most other sensing operations can be done away from the heart of a process, but to measure temperature, probes need to in the action.… Read more

Gas Burner Nozzle

Peak Sensors has recently been supplying a number of customers with Gas Burner Nozzles for use in gas fired glass furnaces.

Gas Burner Nozzle

Gas Burner Nozzle Design

Typically a coarse thread like 5/8″ UNC on a stainless steel shank is secured to a Recrystalised Alumina gas exit.

Peak Sensors normally manufactures temperature sensors. The materials and construction techniques used for a gas burner nozzle is very similar to thermal probes.

Peak Sensors

Peak Sensors supplies temperature sensors and thermocouple cable for many industrial applications. Working with customers to design bespoke sensors is our core strength.  We welcome any enquiry concerned with temperature measurement.… Read more

Custom Built Temperature Sensor

The vast majority of contact Temperature Sensors have to be fully immersed in the specific process to be monitored. Probe design must consider application temperatures, pressure constraint, process medium, signal connection and a range of other constraints. This creates a demand for custom built temperature sensor designs.

Experience of Custom Built Temperature Sensors

Peak Sensors staff have built up an extensive knowledge of temperature solutions through experience over the years. There are common design themes, but most products we supply are custom built temperature sensors, unique to a specific customer.

This focus on Custom built temperature sensors allows us flexibility to respond to new requirements.… Read more

Thermocouple Fundamentals

A Thermocouple consists of two different conductors. Joined at the measurement point, they produce a voltage because of the thermal gradient passed through. If no net gradient exists, no voltage is generated.

Thermocouple Basics

Thermocouples can cover the measurement range – 270 to + 2320 °C. This useful width and the basic simplicity of the device make thermocouples the dominant temperature sensing technology. A thermocouple does not need a power supply. The conductors alone create a small voltage, this signal, being electrical, can easily be used as a system input.

Thermocouple Pairs

Different conductor pairs are defined as standard sensor types.… Read more

Temperature Sensor Design, Costs and Constraints

Contact temperature sensors are often described as simple devices. Thermocouples are indeed just two pieces of different metal joined at a measuring point. Resistance thermometers are almost as simple in principle. A good Temperature Sensor Design however will consider much more.

While the measuring component of an assembly is simple in principle,  a good temperature sensor design must provide the sensing part with support, insulation, environmental protection, process connection and a termination point. Consideration toward adequate immersion and immunity from other sources of error are also needed. Anticipated sensor lifetime needs consideration as well as cost.

Temperature Sensor Design

Design is always a compromise.… Read more

Element and Assembly Resistance Thermometer Accuracy

Resistance Thermometer, Pt 100, RTD, whatever you call them, are devices that change resistance with temperature. They are available in a number of defined accuracy bands.

European Resistance Thermometers are usually available as 100Ω at 0°C and 138.5Ω at 100°C according to BS EN 60751 with a linear resistance change within and beyond these temperatures. Resistance Thermometers can be set to 500 or 1000 Ω

Elements can be rated to -200°C and up to +600°C.

RTD’s can be more accurate than Thermocouples, however the expected accuracy of an assembly can easily be misunderstood.

Common Resistance Thermometer Element Types

The Pt 100 sensing element is available in a number of forms:

Thin Film elements are the volume leader inexpensive device.… Read more

Ceramic used in High Temperature Sensor Designs

Temperature Sensors operating above 1100°C normally use ceramic protection sheaths and insulators. The most useful ceramics for temperature sensors are Recrystalised alumina and Aluminous Porcelain.

Recrystalised Alumina Ceramic

Recrystalised Alumina is commonly called RA, Alsint ®, RUBALIT ®  , AluSIK-99 ZA ®, 

RA is the higher temperature grade, with applications up to 1700°C. The specification most usually referred to is DIN 799. A similar grade DIN 710 is now no longer readily available, but it is still seen on older thermocouple specifications sheets. DIN 799 grade is minimum 99.7% Al2O3. Some ceramic shape manufacturers claim 99.8%. My understanding is that the basic raw material before extrusion is 99.8%.… Read more