What is a thermocouple? 1010PAE 1010PWE 1016PSEM 1016PSE A thermocouple is a device designed for temperature measurement, based on thermoelectric effects, which allows it to measure temperatures above 2,000° C and below -250° C, depending on the materials with which it is manufactured. It is a circuit formed by two conductors of different metals or […]
Article 500 Hazardous Locations, Classes I, II, and III, Divisions 1 and 2 Articles 500 through 504 cover the requirements for electrical and electronic equipment and wiring for all voltages in Class I, Divisions 1 and 2; Class II, Divisions 1 and 2; and Class III, Divisions 1 and 2 locations where fire or […]
FM: FACTORY MUTUAL The Factory Mutual Approvals Division determines the safety and reliability of equipment, materials or services utilized in hazardous locations in the United States and elsewhere. For a product to receive FM approval, it must meet two criteria. Initially, it must perform satisfactorily, reliably and repeatedly as applicable for a reasonable life expectancy. […]
The IECEx System is a set of four separate Schemes (of which one relates to Ex Equipment) that were developed to satisfy the calls from the Ex industry for international recognition and coordination of the outputs of various certification systems and test laboratories (house) with different practises with different levels of expertise. The IECEx scheme […]
Many information must be reported on the marking plate of equipment and components addressed to hazardous areas which often cause several doubts and also disagreements among technicians and inspections supervisors. The EN 60079-0 standard brings the general Rules about electrical equipment for explosive atmospheres due to the gas presence. The information which must be reported […]
ATEX or IECEx certified products are essential in any location that may contain, or has activities that produce explosive or potentially explosive atmospheres. There are a number of places that could be defined as being in an explosive atmosphere, some more obvious such as an oil rig, and others that you might not think of […]
To all customers Using metric threads, Please be advised that the part numbers have changed for some configurations Please see below-attached sheet regarding the new part numbers
The ATEX code is an alphanumeric string that denotes the certification achieved by the product along with the environment and conditions it is suitable for. The code can be broken down into a prefix, for example: CE0518 Ex II 2 G and suffix, for example: Ex d IIC T6 Gb. Products may carry more than […]
NEMA is an acronym for National Electrical Manufacturers Association. This organization gives electrical component enclosures ratings — such as NEMA 4X — based on their protective qualities. NEMA ratings specify whether an electrical component enclosure is safe for outdoor use, and what type of environmental conditions it can withstand.
Watertight. Must exclude at least 65 GPM of water from 1-in. nozzle delivered from a distance not less than 10 ft for 5 min. Used outdoors on ship docks, in dairies, and in breweries.
It is often difficult and confusing for engineers to know what type of rating they need to look for when they desire to have a “waterproof” enclosure. There is a big difference between waterproof, water resistant, and other but not specific certifications. To help out, there are several rating systems that have been developed by several testing agencies that verify the results. Among these, the two best known are NEMA and IP. Today will deal only with the IP system.
HAZARDOUS AREA SENSORS CERTIFICATION Thermocouples and RTD Sensors are a source of Ignition Electrical equipment including temperature sensors for use in Hazardous Areas needs to be designed and constructed in such a way that it will not provide a source of ignition. This equipment should be fully tested and certified with a certificate of compliance issued by an Independent Authority.
Explosion Proof classification for a sensor/transmitter means that the housing has been engineered and constructed to contain a flash or explosion. Such housings are usually made of cast aluminum or stainless steel and are of sufficient mass and strength to safely contain an explosion should flammable gases or vapors penetrate the housing and the internal electronics or wiring cause an ignition.
likewise, no system is explosion proof if it contains non-explosion proof components
Instrument engineers are responsible for providing safe and appropriate instrumentation. To declare a system safe, simply because a single component is approved, is dangerous in more ways than one.
Installing a temperature sensor in a hazardous location requires more than an approved explosion proof connection head. To meet the safety requirements of FM, you must consider the complete system: including the sensor, the thermowell (if required and used) and the connection head.
Each component in the system must meet the code. For example, many thermowells are supplied with 1/2-14 NPSM threads for the sensor connection. FM dictates that to meet the requirements for explosion proof, a tapered thread is required.
A thermocouple consists of two dissimilar conductors in contact, which produce a voltage when heated. The size of the voltage is dependent on the difference of temperature of the junction to other parts of the circuit. Thermocouples are a widely used type of temperature sensor for measurement and control and can also be used to convert a temperature gradient into electricity. Commercial thermocouples are inexpensive, interchangeable, are supplied with standard connectors, and can measure a wide range of temperatures.
