Description
Fischer NK10 ATEX – Explosion proof Liquid level switch (Zone 1, 2, 22) for high operating temperature
Explosion proof for Zone 1, 2 (gas explosion), Zone 22 (dust explosion), corrosion resistant with stainless steel float, suitable for high media temperature
Make: Fischer Messtechnik (Germany)
Model: NK10####I (for gas explosion proof Zone 1, 2); NK10#####F (for dust explosion Zone 22)
Fischer NK10 ATEX is accurately monitoring level limit switch. It is suitable for installation at heat and process engineering plants, to ensure lowest permissible liquid level. The instrument meets DIN 4574 requirement as level limiter.
NK10 series instruments are structural tested and have received the DIN registration number / prototype test mark of DIN CERTCO Gesellschaft fur Konformitatsbewertung (company for validation of conformity).

EC prototype tested for application in explosion proof hazardous area
TUV 07 ATEX 553595
- Declaration for application in Zone 1 and 2
Ex II 2 G EEx ib c IIC T6 - zone 22
Ex II 3 D c T80° C IP55
NK10 is prototype tested as level limiter acc. to DIN 32728
- DIN Reg. No. 1D 01602
EC prototype tested acc. to directive 97/23/EC (pressure equipment directive PED) as equipment with safety function
- Certificate no. 07 202 5435Z 0063/2/1
Type approval acc. to guidelines of Germanischer Lloyd for application on ships
- Certificate no. 65 353-93 HH Test Mark
Working Principle:
The stainless steel ball float of level limiter is installed inside the fluid vessel. The float moves when level changes. This movement is transported directly to a microswitch by the float rod. The float rod is sealed by metal bellows and its centre of rotation is outside of the pressure chamber.
A test button is located outside the pressure chamber to enable a function test acc. to DIN 32728 without lowering of level. If the test button is pressed the floated is moved against its buoyancy.
If the instrument is used as level limiter, a locking and unlocking mechanism acc. to DIN 32728 need to be installed into the subsequent electrical control. This safety device must meet demands of DIN 57116 / VDE 0116.
Key Features:
- Corrosion resistant float
- Suitable for high operating temperature up to 400° C.
- Stainless steel material in media contact
- Double wall metal bellows of stainless steel
- Varnish heat resistant
Key Specifications:
- Maximum operating pressure: 10 bar or 16 bar
- Maximum medium temperature: 350° C or 400° C
- Minimum medium temperature: -20° C
- Permissible ambient temperature (explosion proof hazardous area): -20° C ≤ Tamb≤ 60° C
- Max. load data: 250V, 6A
- Electrical connection: internal connector block
- Ingress protection: IP55 acc. to DIN EN 60529
- Minimum specific density: > 0.6 kg/dm3
- Switching hysteresis: approx 6 mm
- Mounting: horizontal
- Float system: Stainless steel 1.4301
- Metal bellows: Stainless steel 1.4541
- Welded socket: St. 35.8
- Flange: 1.0425 (H II) resp, 1.4571
Application areas:
- Monitoring of minimum or maximum filling levels of vessels
- Protection of pumps against dry running
Industrial areas:
- Power plants
- Marine, shipping, ship building
- Water, effluent treatment system