Ashcroft Temperature Instruments

Ashcroft temperature instruments include measurement and control devices crucial to a wide range of applications, including Thermometers, Thermowells, Temperature Switches, Temperature Sensors and Resistance Temperature Detectors (RTDs).

Ashcroft Thermometers

Thermometers are a way to measure process temperature that provides an easy-to-read visual-only display on the indicator. Ashcroft thermometers include bi-metal and gas actuated models. Unlike the simple glass thermometers, neither Ashcroft type uses mercury.

Ashcroft Bi-Metal Thermometers

Ashcroft Bi-Metal thermometers are actuated by a helical bi-metal strip that is built into the mounting stem of the thermometer. They offer accurate, reliable, easy-to-read measurements, and should be hermetically sealed to prevent fogging.

Bi-metal stems and capillaries along with associated thermowells are available in a wide selection of lengths (stems up to 60”)to fit nearly any application. Bi-metal thermometers can read wide temperature range from -80 °F to 1000 °F (although they are not intended for continuous use beyond 800 °F).

Ashcroft bi-metal thermometer models are available with specialized features including:

• liquid fill
• customized dial printing
• silicone-dampened coil to reduce pointer flutter on high-vibration applications

Ashcroft Gas-Actuated Thermometers

Gas-Actuated thermometers use expanding or contracting gas in a closed bulb and capillary system (pressurized approximately 300 psi).  As the temperature increases at the bulb, the gas expands, which increases the pressure inside the system. Gas-actuated thermometers measure temperatures ranging from extreme cold (-320 °F) to extreme heat(1200 °F).

Gas-actuated instruments offer additional features:

• resistance to shock and vibration
• no head or elevation error
• hermetically sealed to prevent fogging
• capability for direct mounting in a thermowell in the process or remote mounting using a capillar

Ashcroft Thermowells

A thermowell protects temperature monitoring instruments from corrosive media, high pressure and velocity.  Ashcroft thermowells protect thermometer stems and bulbs and also allow removal of the temperature measurement instrument without the need to shut down the process. Ashcroft thermowells are available to match nearly any temperature measurement device and fit any installation:

• industry standard threaded, flanged, socket weld, Van Stone, weld-in and sanitary
• a wide variety of lengths
• multiple materials

How Are Thermowells Used?

Thermowells are made from solid metal bar stock. Each thermowell has an opening on one end where the temperature instrument, such as a bi-metal thermometer, gas-actuated thermometer, RTD or thermocouple, can be inserted. The thermowell acts as a heavy metal jacket to prevent damage to the instrument.

Thermowells are used in industrial applications that require monitoring extreme temperatures of air, gas or liquid in challenging environments such as Refineries, Oil & Gas, Chemical Plants, Wastewater Facilities, Power Plants.

Contact Carotek for any assistance selecting the right Ashcroft thermowells for your application requirements:

• material (of process media as well as application piping/vessel)
• media temperature
• process flow
• flanged, threaded, or welded connection type
• size
• straight, tapered, or stepped shank type

Ashcroft Temperature Switches

Ashcroft® temperature switches control high and low temperature operating limits.These accurate and reliable temperature measurements are critical to the safety and efficiency of your process. Ashcroft temperature switches are used to:

1.Monitor and control the temperature status of a system to prevent overheating or overcooling

2.Protect equipment from becoming damaged

Temperature switches are simple and easy to install, and are available in a variety of configurations.

Options include:

• NEMA 4 and NEMA 7 temperature switches
• OEM temperature switches
• water tight temperature switches
• explosion-proof temperature switches
• differential pressure switches

How Do Temperature Switches Work?

Mechanical temperature switches require no power source. When a temperature switch senses a change in an application’s temperature level, it mechanically opens or closes the switch contacts at a pre-determined point. This action either maintains the desired temperature or indicates an out-of-limit condition.

Ashcroft Thermocouples/Temperature Sensors

Ashcroft thermocouple sensors and thermocouple assemblies feature a simple design that makes them remarkably versatile, reliable and cost-effective. These devices are used to monitor temperature inindustrial, process and hazardous installations. A host of options ensure that Ashcroft thermocouples are configurable to the requirements of nearly any installation.

• Available with E, J, K, N & T type thermocouples
• for use with either DIN 43772/T.2 or ISA-ds 49 style thermowells
• for use with DIN and ASME type lag extensions
• wide selection of aluminum and 316 stainless steel connection heads

What is a Thermocouple?

A thermocouple consists of two wires of dissimilar metals (such as iron and copper-nickel).The two wires are welded or twisted together at one end. This joint (junction)needs to come in contact with the temperature source to measure its temperature. In some installations, the wires are embedded in the sheath of a rigid or flexible probe that protects the device and allows for easier installation, especially when inserted into a thermowell.

Ashcroft RTDs

A resistance temperature detector, or RTD, is a sensor that measures process temperature and provides an electronic signal of the temperature reading that can be sent to the control system or locally indicated using a transmitter with a display.

Ashcroft® RTD sensor assemblies monitor temperature in industrial, process and hazardous installations, with features that make them configurable to the requirements of nearly any installation.

• Available with Pt 100 and Pt 1000 RTDs
• Designed for use with either DIN 43772/T.2 or ISA-ds 49 style thermowells
• Designed for use with DIN and ASME type lag extensions
• Offered with a wide selection of aluminum and 316 stainless steel connection heads

How Does an RTD Work?

RTDs are known for their highly accurate and repeatable measurements, are made with either a thin film or a wire wound circuit. The resistance of the RTD element changes as the temperature in the application changes.  RTDs are slightly narrower in temperature range than thermocouples.

Offshore Oil Rigs, Chemical and Petrochemical Plants, Pulp and Paper Mills, Power Plants, Steel Mills, Water and Sewage Treatment Facilities, Pumps, Compressors and Turbines, Boilers and Burners, Degreasers and Evaporators, Recovery Systems, Reverse Osmosis Systems / Filters, Food Processing, Ground Support Equipment, Hydraulic and Lubrication Systems, Heating and Air Conditioning, MarineEquipment, Specialized OEM Equipment, Refineries, Dairies and Breweries, Filters and Presses, Paint Spraying Equipment, Pharmaceutical/Biotech, HVAC, General Industrial, 
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