What is intrinsic safety?

Intrinsic safety - definition

Intrinsic safety is an approach to the design of electrical equipment that prevents explosions by ensuring that the energy (e.g. electrical sparks, hot surfaces) transmitted to the hazardous area is significantly less than the energy required for an explosion hazard.

Intrinsic safety is a required standard for devices that are used in highly volatile areas that may include flammable gases, powders or fuels.

Why is intrinsic safety important?

Taking care to meet intrinsic safety standards in industry is an important part of protecting people, installations and products from risk. High-quality measurement and control technology has a preventive function in industrial systems.

Intrinsic safety requirements – facts and myths

In the area of intrinsic safety, many myths have grown up and many mistakes are made. So we outline some of the most important requirements you need to bear in mind:

Adding an IS interface does not make a device intrinsically safe. Reducing the risk of explosion can only be achieved by installing equipment that has been specifically designed to meet IS requirements, together with a suitable IS interface.

Pay attention to the cables! Because cables have inductance and capacitance, and thus energy storage capacity, they can affect the safety of the system. It is important that the capacitance and inductance of the cable and field devices are less than the capacitance and inductance allowed for the IS interface for the gas group in which the device is installed. It is usual to calculate the maximum cable length allowed for the installation.

The first check should be carried out shortly after installation of the appliance. Thereafter, regular periodic checks should be carried out throughout its lifetime. This is to detect damage or unapproved replacement of IS components.

Intrinsically safe devices vs. explosion-proof equipment

Explosion-proof equipment is capable of stopping an explosion inside an enclosure so that flames or hot gases do not escape. The term "explosion-proof" does not mean that the product is able to withstand a strong external force.

Intrinsically safe electronic devices, on the other hand, are low enough in power that they will not cause an explosion.

Advantages of intrinsically safe equipment

• avoidance of the cost, size and laborious installation of explosion-proof enclosures

• maintenance and diagnostic work can be carried out without shutting down production and ventilating the area

• potentially lower insurance premiums due to reduced risk

JUMO intrinsically safe equipment to hazardous environment

JUMO offers instruments in intrinsically safe design. These instruments are approved for use in hazardous areas.

Ex-i isolation switch amplifier

The JUMO Ex-i isolated switching amplifier provides reliability, galvanic isolation and safe transmission of switching signals in a wide range of applications. It can be installed in Ex zone 2 and used with a sensor in zone 0.

Special features of the JUMO Ex-i isolation amplifier

Safe transmission of switching signals even from Ex areas

• High degree of process reliability due to intrinsically safe inputs, three-way galvanic isolation and line fault detection

• Space saving in the control cabinet due to the two-channel version

• Reduced storage costs due to wide permissible supply voltage range

• Reduced start-up time due to screw terminals and simple configuration via DIP switches

• ATEX and IECEx approval, installation possible in zone 2, sensor in zone 0

• Extended ambient temperature range from -40°C to 60°C

JUMO offers the optimum complement for the reliable transmission of level information - the JUMO NESOS series.

Temperature and humidity sensor for industrial applications

Intrinsically safe JUMO temperature and humidity sensors are designed for demanding industrial applications, including use in hazardous (ATEX) areas. The devices perform reliably in harsh process conditions, offering high measurement stability and flexible configuration thanks to interchangeable process probes.

Special features of the temperature and humidity sensor for industrial applications:

• relative humidity measurement over the full range from 0 to 100% RH
• temperature measurement range from -70 to +180 °C (depending on the probe type)
• resistance to process pressure up to 100 bar (depending on the probe version)
• intrinsically safe design for use in hazardous areas
• rugged metal housing in an industrial design
• interchangeable intelligent probes with various process connections
• housing with LCD display and operating keypad (depending on version)
• very high accuracy, long-term stability, and resistance to condensation
• capability to calculate and output derived values such as dew point, wet-bulb temperature, absolute humidity, mixing ratio, water vapor pressure, and enthalpy

The intrinsically safe JUMO 907037 sensor is used, among others, in the pharmaceutical, petrochemical, and food industries – wherever safe and accurate measurement of temperature and humidity parameters under industrial conditions is required.