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Rototherm manufactures a wide range of temperature switches with both electrical outputs and pneumatic outputs. These include ATEX certified temperature switches suitable for use in hazardous areas.
Series 700 is a mechanical temperature switch - the Series 800 temperature switch is an electronic device that also functions as a temperature indicator and transmitter. Both are available with aluminium or stainless steel housings and either direct or capillary mounting.
Series 700 Temperature Switch
Designed to complement the extensive Series 700 Pressure and DP switches, Series 700 Temperature Switches offer accurate, reliable switching in a robust cast enclosure.
RANGES FROM –50°C TO +400°C
Both vapour filled and gas filled systems are available. Vapour filled systems have the advantage of negligible ambient temperature effects on the switching point. Gas filled temperature systems provide larger ranges and are more suited to applications where switching points are close to ambient temperature.
WIDE RANGE OF OUTPUT SWITCHES
The wide range of electrical output switches available includes gold contacts for low current d.c. and silver contacts for high current a.c. A single pole double-throw microswitch (SPDT) can make or break a circuit at the required switching point. Dual switches (2 x SPDT) can make or break two independent circuits at the same or different switching points.
Versions are also available for electrical switching in hazardous areas and pneumatic switching.
DIRECT AND REMOTE MOUNTING VERSIONS AVAILABLE
Direct mounting (as shown opposite) allows the switch to be screwed directly into a thermowell (pocket). With remote mounting versions the temperature bulb is secured in the thermowell and connected to the switch housing via a capillary tube. Both types are available with aluminium housings for general industrial use or stainless steel housings for ultimate protection from the environment. The temperature system in all versions is fully welded in 316 Stainless Steel.
The setpoint of the switch is adjusted by means of a capstan head screw, located within the lower section of the enclosure. As the main cover does not need to be removed, adjustment can be made even when the switch is energised.
ACCURACY AND REPEATABILITY
These switches provide excellent repeatability and long in-service life. In addition switching differentials are typicallybe low 2% of range.
Series 700 Temperature Switch
with electrical output for non-hazardous areas
These temperature switches are designed to provide electrical output switching for non-hazardous area applications.
Series 700 Temperature Switch
for Pneumatic Control Applications
Pneumatic Output Pressure Switches provide the switching of a compressed gas supply (generally air) at a
Series 700 Temperature Switch EExd Version
for Potentially Explosive Atmospheres
These pressure switches are designed to provide electrical output switching for Potentially Explosive Atmosphere applications.
Series 800 Smartstat
Electronic Pressure / Differential Pressure Switch & Transmitter
The Series 800 Smartstat is a microprocessor controlled switch, transmitter and indicator, which enables several instruments to be replaced with a single device. Smartstats are available for the measurement of pressure / differential pressure (P & DP) and temperature (T).
Replacing a transmitter, switches and a gauge with a single Smartstat reduces equipment costs. Additionally there are reductions in documentation, installation time/ fittings/cabling, and calibration/maintenance costs.
The Smartstat provides greater accuracy and repeatability than a conventional mechanical switch. Very large and very small switching differentials can be achieved without compromising accuracy.
Ease of Calibration
Pushbutton calibration of switch setpoints and 4-20mA calibration can be carried out on site without additional test equipment or tools.
Because the Smartstat is microprocessor based additional features are easily provided through the software including:
• Programmable switching delays - the switching on or off (or both) of the relays may be delayed from 0.5 seconds to 15 minutes. This is particularly
useful for preventing unwanted switching due to pressure transients.
• Display of MAXimum and MINimum pressures recorded by the Smartstat.
• Display of transmitter output in mA.
• Reversal of transmitter output 20-4 mA instead of 4-20 mA.
• Square-root extraction to provide 4-20mA output proportional to flow using a DP Smartstat.
• Displayed units of measurement - can be changed by the user as required.
Series 800 Smartstat Temperature Switch
There are some temperature switching applications that are very demanding due to the need for:
• Very high (or low) temperatures.
• High accuracy and repeatability.
• Very large (or small) switching differentials.
• High frequency switching operation.
• Low frequency switching operation (once per year).
• Regular need to change switching temperatures.
These requirements may exceed the capabilities of conventional mechanical temperature switches, the Smartstat was designed to overcome these problems.
• Smartstat RTD elements can be used to provide ranges from -200°C to 400°C.
• Typical repeatability is 0.1%.
• Two independent single-pole, double-throw (SPDT) relays are fitted in the Smartstat, the operating points of which can be set anywhere within the range. The switching differential can be set from 1 digit to 100.0% of range without loss of accuracy.
• Being almost entirely ‘solid state’ the Smartstat can provide up to 100,000,000 switching operations. It can respond to changesin temperature more rapidly than a mechanical temperature switch.
• With a mechanical switch testing the operation regularly is the only way to ensure that it is operating correctly. With the Smartstat the continuous temperature display serves to indicate that the device is operating correctly and will switch when required.
• Pushbutton calibration of switch setpoints can be carried out on site without additional test equipment or tools.
• In addition to its function as a high accuracy temperature switch the Series 800 Smartstat also functions as a temperature transmitter and temperature indicator enabling significant cost savings as several instruments can be replaced with a single device.
Rototherm Group is a leading manufacturer of instrumentation to measure and control temperature, pressure, flow, level and density
Registered in the UK 2570730
© Rototherm Group 2013