ATEX Radar Level Sensors for Hazardous Area Level Measurement

Some tanks hold water. Others hold naphtha, solvent or fine grain dust. In that second group, one spark can end the whole plant. This is why an ATEX certified radar level sensor is a basic safety part of the plant.

A radar level sensor fires a small microwave pulse at the product surface. The pulse bounces back. The device gives the time of that trip and tells how full the vessel is. Nothing touches the liquid. Nothing spins or floats. This is important for a hazardous area.

What Makes a Radar Level Sensor Safe for Explosive Areas

Safety here comes from two things. First, where the device is attached. Second, how it is built. Both points are covered below.

⚠Hazardous Zones in Plain Words

Plants are split into zones based on risk. Gas zones and dust zones are numbered in different ways.

⚠  Zone 0: an explosive gas mix is there almost all the time

⚠  Zone 1: gas is likely during normal work

⚠  Zone 2: gas shows up rarely, and only for short periods

⚠  Zone 20, 21 and 22: the same idea, but for combustible dust

A tank of ethanol may be Zone 0 inside and Zone 1 outside. So the antenna and the housing can carry different ratings. Always check both.

Protection Methods Used in a Radar Level Transmitter

Intrinsic safety works by limiting the electrical energy in the circuit so no spark or hot surface can ignite the atmosphere, even under fault conditions. That method is marked Ex i.

Ex ia protects against two faults at once and suits Zone 0, Zone 1 and Zone 2. Ex ib covers one fault and is used in Zone 1 and Zone 2. Flameproof units are marked Ex d. An Ex d housing is built to contain an internal explosion and stop it from reaching the outside air.

A quick way to choose:

Why Radar Wins Over Other Level Methods

Older methods still work, but they struggle in tough vessels. Here is how the main options compare.

◎Vapour, Foam and Dust Do Not Stop the Beam

Ultrasonic units slow down in hot vapour. Floats jam when the product is sticky. Microwaves ignore most of this. A radar level transmitter keeps reading through steam, light foam, and heavy dust clouds.

✱Fewer Failures Means Fewer Entries

Every tank entry in a live plant carries risk. A sealed radar level sensor has no float to clean and no cable to snap. That cuts confined space work and permits paperwork.

How to Read the ATEX Label Before You Buy

The marking on the tag tells you exactly where the unit may go.

▣Marking Example: II 1/2 G Ex ia IIC T6 Ga/Gb

IIB covers ethylene, propane, methane and most common hydrocarbons, while IIC is the highest group. A sensor marked IIB must not be used in an IIC gas area. That single letter has stopped many bad purchases.

Industries That Depend on These Sensors

Any site with flammable stock fits the profile. A few common examples follow.

◆  Oil and gas: Crude tanks, slop tanks, separator vessels

◆  Chemicals: Solvent drums, reactors, acid storage

◆  Grain and feed: Silos where fine dust builds up

◆  Paint and coatings: Thinner and resin batching

◆  Wastewater: Digesters that give off methane

◆  Pharma: Alcohol storage and clean process tanks

Installation Tips That Keep Readings Steady

Most complaints trace back to mounting, not the device. To prevent this some of the tips are given:

⚙Mounting Rules

▸  Keep the antenna clear of the nozzle bottom

▸  Stay away from the tank wall by roughly one sixth of the diameter

▸  Never aim at the fill stream or an agitator

▸  Skip the centre of a domed roof, as echoes gather there

▸  Fit a sun shade outdoors to protect the housing

⚡Wiring and Loop Care

✓  Run intrinsically safe wiring in its own tray, marked blue

✓  Use a certified barrier or isolator on the safe side

✓  Bond the shield at one point only

✓  Keep cable capacitance within the values on the certificate

✓  Store the ATEX certificate with the loop folder for audits

A radar level transmitter set up this way will run for years with only a yearly check.

Meet the Manufacturer Behind These Instruments

Kaidi Sensors has spent more than 20 years in industrial automation. The team builds level, flow, pressure, and temperature instruments from a factory in Zhuhai, China. Level measurement is the core skill, and radar is the flagship line.

What buyers tend to value:

★  Range and accuracy: up to 80 m of range with accuracy near ±1 mm

★  Frequency choice: 6 GHz through 120 GHz under one roof

★  Tough housing: die cast aluminium that resists moisture and sun

★  Service life: typically 3 to 5 years, based on duty

★  OEM and ODM: badge, firmware, and fitting changes on request

★  Wide catalogue: radar, ultrasonic, magnetic level gauges, and tuning fork switches

Engineers can also pair a primary radar level sensor with a fork switch for high level alarm. That gives you a second layer of protection on critical tanks.

⇄Pick the Right Frequency with Kaidi Sensors

Browse the full radar level meter lineup to match your flange, range, and output.

FAQs

QIs ATEX the same as IECEx?

No. ATEX is the European law. IECEx is a global scheme. Many units carry both, which simplifies export projects.

QCan one radar level sensor cover Zone 0 and Zone 1?

Yes. Dual marking such as Ga/Gb allows the antenna to sit in Zone 0 while the head sits in Zone 1.

QDoes foam ruin the reading?

Thick foam can weaken the echo. Guided wave versions cope better because the signal travels along a probe.

QWhat output should I order?

Most plants pick 4 to 20 mA with HART. Modbus RTU is common where a PLC gathers data from many tanks.

QDo I need a barrier with an Ex ia unit?

Yes. The barrier is part of the safety system. Without it, the intrinsically safe rating does not hold.

QHow often should the unit be checked?

A yearly visual check and echo review suits most sites. Dusty silos may need a look every six months.

Ready to Spec Your Next Project?

Hazardous area level measurement comes down to a few clear choices. Match the zone to the right protection method. Match the frequency to the vessel and the media inside it. Check the label before you sign the order.

A radar level sensor gives you a non contact reading that holds up through vapour, foam, and dust. Paired with sound mounting and proper wiring, it becomes one of the lowest maintenance parts on the tank. That reliability is exactly what keeps a hazardous site running safely, shift after shift.

➤Contact the Kaidi Sensors today and get your ATEX radar level measurement sorted properly.