Sensors and switches used to monitor machinery must be approved for use in the location in which the machine they are monitoring resides.  The National Fire Protection Agency defines these locations as 4 types.  First is a standard location meaning there is a normal atmosphere without danger of explosion.  The second location type, called Class I, is where explosive gases exist.  The third location type, called Class II, is where combustible dusts are present.  The fourth location type, called Class III is where combustible fibers or flyings are present.  Sensors and switches used in these hazardous locations require testing and certification by a Nationally Recognized Test Laboratory. Several methods of protection may be used in the construction of the sensor or switch, these methods include explosion-proof or dust ignition-proof enclosures, or intrinsically safe design.  Explosion-proof enclosures can safely contain and then vent an explosion inside the enclosure, this method is for use in Class I locations.  Dust ignition-proof enclosures prevent dust from entering the enclosure and maintain a cool surface temperature when covered in dust, this method is for use in Class II locations.  Sensors designed to be intrinsically safe use very little power so that there is not enough energy present in the circuitry to ignite the explosive atmosphere in the event the sensor or wiring is damaged.  Please contact Electro-Sensors, Inc. for assistance in choosing the best sensor or switch for your application with regards to performance and the type of location it will be used in.

Electro-Sensors makes many Speed Switches, each speed switch is designed to fit a particular application.  Electro-Sensors makes Speed Switches that are Explosion-Proof/Dust Ignition-Proof and come in both 2-piece and 3-piece systems.  The M100T is a standard Speed Switch with Explosion-Proof/Dust Ignition-Proof ratings and a built in sensing head.  The SCP Speed Switch has a built in Sensing head and up to 2 relay outputs, It is rated Explosion-Proof and Dust Ignition-Proof.  The UDS Speed Switch is a Explosion-Proof/Dust Ignition-Proof Speed Switch with the ability to sense Reverse Speed.  The DR1000 is and Explosion Proof Speed Switch which is compatible with 3-piece systems.  The FB420 is a Speed Switch that also has 4-20 mA output alongside a relay, The FB420 is Explosion-Proof and Dust Ignition-Proof.  

Electro-Sensors makes Speed Sensors that can operate in classified areas including Class I and Class II environments.  These sensors are certified Intrinsically safe and when correctly installed with an IS barrier provide the highest level of safety for a Speed Sensor.  The ST420 is a Speed Sensor that generates a proportional 4-20 mA output based on the speed of a target.  The ST420 meets Class I, Div I (C, D) Class II, Div I (E, F, G) when used with an IS barrier.   There is also a ST420 Sensor Family that uses Dust Ignition-Proof Ratings as its method of protection, this is for use in Class II environments dealing with hazardous and flamable dusts.  The Series 18 group of Speed Sensors  are FM Approved Intrinsically Safe (IS) Class I, Div 1, A → D; Class II Div 1 E→G; Class III sensors that can provide an NPN or PNP output.  The 931 Speed Sensor is Explosion-Proof and Dust Ignition-Proof and provides an NPN square wave  output signal.  

Electro-Sensors makes Temperature Sensors for both Intrinsically Safe and Dust-Ignition Proof Applications.  Dust-Ignition Proof Temperature Sensors  have a conduit adapter for easy connection to conduit.  This allows for straight forward installation in order to meet Class II & III environmental requirements.  When Class 1 Temperature requirements are needed Electro-Sensors provides Class I, Div I (C, D) Class II, Div I (E, F, G) Temperature Sensors via Intrinsic Safety.  These Sensors when paired with IS Barriers provide the highest level NFPA ratings for Temperature Sensors.   Temperature Sensors are offered in  probe & Surface mount styles.  Probe options designed for use in pillow block bearings come with a zerk fitting for easy greasing of the bearing.  

Electro-Sensors makes Position Monitors that among other things can monitor gates, valves, distributors, and clam shell buckets.  The SG1000 comes in 6 different resolutions, each tailored for a different type of application.  There is a relay based version for our standard application that allows for machinery shutdown rather than data output.  All SG1000 models are certified Explosion-Proof and Dust Ignition-Proof with a rating of Class I, Div I (C, D) Class II, Div I (E, F, G), Class III.