Rosemount 2521 Solids Level Switch (High-Sensitivity Vibrating Fork)

Rosemount1 configuration

Configure Your Rosemount 2521 Tuning Fork Solids Level Switch

Vibrating-tuning-fork solids point-level switch for fine-grained powders and granulates. High-sensitivity piezo-electric oscillation continuously monitored — fork frequency shifts when product covers it. Ideal for cement, lime, flour, plastic pellets, grain, and other low-density powders where rotating-paddle (2501) is over-spec or capacitance (2555) is fooled by high-dielectric coatings.

Required Specifications

11 of 11 selected

Fork Profile*

Thermal Profile*

Process Connection/Thermal Extension Tube*

Conduit Entry / Cable Threads*

Fork Length*

A00000

Process Connection Size*

Process Connection Rating*

Process Connection Type*

Electronic Type*

Product Certification*

Rosemount 2521 Tuning Fork Solids Level Switch Part Number

2521SMS42NNGKA00000NANA

Configured list price:$1,468.05(estimate based on May 2026 Rosemount list; quote may reflect distributor pricing)

Configuration Summary — Rosemount 2521 Tuning Fork Solids Level Switch

Base: $1,207.18

Fork Profile:: SStandard Sensitivity, 50 g/l (3 lb/cubic ft) dry and wet applications
Thermal Profile:: MWithout extension tube (up to Tproc = 150°C (302°F) at Tamb < 40°C (104°F))
Process Connection/Thermal Extension Tube:: S316L Stainless steel (1.4404)
Conduit Entry / Cable Threads:: 4NPT 1/2-in. tapered ANSI B1.20.1 (1off conduit + 1off Ex-d blind plug)+$30.64
Process Connection Size:: 22in / 50mm (DN50) / 50A
Process Connection Rating:: NNFor use with non-flange process connection type
Process Connection Type:: GBSPP (G) Thread
Electronic Type:: KNAMUR+$230.23
Fork Length:: A00000Standard Length 6.47in (165mm)
Product Certification:: NANo hazardous location certifications
Product Certification:: NANo hazardous location certifications

Rosemount is configurator-heavy and quote-only — Valley Instrument verifies option compatibility, lead time, and pricing before confirming your order.

Pre-configured Options(1)

Rosemount

2521 Solids Level Switch (High-Sensitivity Vibrating Fork)

High-sensitivity variant of the 2511 vibrating fork — same proven fork-resonance technology, tuned for extremely low-density bulk media (below 0.3 lb/ft³ / 5 g/L). Catches the fork frequency change even when very light powders or fluffy materials touch it. Best for low-density polymers, fluffy fines, light insulation media, and other powders where the standard 2511 might miss the trigger. Operates up to 150°C. Same process connections, fork extensions, electronics options, and approvals as the 2511.

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