IFM LMT102 Hygienic Capacitive Point Level Switch

LMT102 (LMCCE-A12E-QSKG-2/US) is IFM’s hygienic capacitive point level detection sensor. It has no vibrating tuning fork structure and features foam and build-up suppression, specially designed for food and pharmaceutical CIP cleaning applications.

✅ Core Overview

Measuring principle: Capacitive (not tuning fork)

Probe length: 38 mm (measured from the cone sealing surface)

Process connection: G1/2 hygienic cone seal, dead-zone free hygienic design

Factory preset: Aqueous media (beer, beverages, cleaning solutions and other water-based liquids)

Communication: IO-Link V1.1 COM2, 38.4 kBaud. Supports parameter read/write, media teach-in and diagnostics

Application: High/low level alarm, overfill prevention, empty tank detection; capable of two-media differentiation (e.g. distinguish product from CIP cleaning fluid)

📋 Key Technical Specifications

Electrical

Supply: 18…30 VDC, reverse polarity protection, short-circuit / overload protection

Output: 2 configurable switching outputs, PNP/NPN selectable; NO/NC configurable via software

Max load per channel: 100 mA

Response time: ＜0.5 s

Temperature

Continuous medium temperature: -20 ~ +100 ℃

Short-term CIP resistance: up to 150 ℃ (1 hour)

Wetted Materials

Main body: 316L (1.4404) stainless steel

Probe tip: PEEK (low adhesion, resistant to material build-up)

Seals: FKM fluororubber

Hygiene certifications: EHEDG, 3-A, EC 1935/2004, compliant for food contact

Mechanical & Protection

Dimensions: Φ30, total length 125 mm, weight 202 g

Protection class: IP67

Mounting: Hygienic cone seal; requires matching hygienic adapter, no stagnant dead zones

✨ Core Advantages (Compared with Tuning Fork)

1. Foam / sediment suppression: Algorithm compensation prevents false triggering caused by foam and tank wall deposits, ideal for beer, dairy and sugar liquid applications
2. No mechanically vibrating components, no fatigue fracture; longer service life under frequent CIP cleaning cycles
3. Dual threshold teach-in: Media calibration via IO-Link or Teach input to differentiate two media with different dielectric constants
4. Full parameters remotely readable/writable: Switch point SP, reset point rP, output mode, diagnostic information
5. Local LED status indicator for straightforward commissioning

🧪 Suitable Media & Industries

Suitable for: Water-based liquids, beer, fruit juice, dairy products, dilute sugar solutions, CIP acid/alkaline cleaners, viscous aqueous media

Industries: Food & beverage, pharmaceutical, biotech, hygienic fluid processes

Not recommended for pure oil or low-moisture powders (use LMT110 for these applications); prefer LMT121 for high-sugar / high-salt media

🛠 Installation & Commissioning Guidelines

1. Mounting position: The probe must be immersed in medium to trigger. Top-of-tank mounting for high-level overfill protection, bottom mounting for empty tank protection
2. Avoid areas with strong agitation vortices or heavy tank wall accumulation
3. Calibration methods:

Local Teach button teach-in

Remote teach-in via IO-Link master (PLC) for one-click threshold setup for two media

4. Do not strike the PEEK probe tip mechanically to prevent cracking

⚠️ Common Troubleshooting

1. False triggering by foam: Re-run media teach-in and increase media compensation parameters
2. Unstable switch point: Check supply voltage drop, confirm proper G1/2 cone sealing; avoid protruding gaskets creating dead zones
3. IO-Link communication failure: Verify wiring, baud rate and sensor address; check cable shield grounding
4. Drift after high-temperature CIP: Confirm FKM seal temperature limits and avoid prolonged exposure above 150 ℃

📌 LMT Series Selection Reference

📎 Alternative Options

Same principle IFM models: LMT100 / LMT104

Tuning fork alternatives: IFM LMT202 (G3/4), LMT302 (G1); E+H, Krohne hygienic tuning forks

Note: Tuning forks cannot suppress foam. Tuning forks are not recommended as replacement for LMT102 in foamy media

HS Code reference: 90261000 (liquid level measuring instruments)

IFM LMT102 IO-Link Parameter Table (SP/rP, Media Teach-in, Diagnostic Codes)

Communication specification: IO-Link V1.1, COM2, 38.4 kBaud; reference baseline: air = 0%, tap water =100%; minimum hysteresis 2%. Writing will be rejected if SP ≤ rP.

1. Core Threshold Parameters (OUT1 / OUT2)

1. Output Configuration Parameters

III. Media Teach-in System Commands (IO-Link Commands, Core of Calibration)

Teach-in logic: Fill tank with medium → send tSP1 command. Sensor learns dielectric constant and writes thresholds automatically. Dual-medium scenario: tSP1 for product, tSP2 for cleaning fluid. Two outputs identify each medium separately.

1. Process Data (4-byte Input)

Byte 0: OUT1 status bit + OUT2 status bit

Byte 1: Sensor status / fault flags

Bytes 2~3: Raw capacitive measured relative value (0~100% level equivalent)

PLC reads this PD to obtain real-time level percentage + two switch states + fault information

1. Device Identification Information (IODD)

Vendor ID: 310 (IFM)

Device ID: LMT series corresponding device number

Supports IO-Link Data Storage: Master automatically backs up parameters; one-click restore after sensor replacement, no on-site re-teach-in

1. IO-Link Diagnostic Fault Codes

36350 / 36351 are test alarms only for factory production testing. They do not appear under normal site conditions and require no action.

VII. Commissioning Best Practices

1. On-site physical media teach-in (tSP1/tSP2) is preferred over manual SP percentage entry. For foamy and build-up prone media, on-site teach-in activates the built-in media compensation algorithm.
2. Parameter lock: Keypad lock available to prevent accidental parameter modification on site.
3. SIO mode: When IO-Link is disabled, sensor automatically switches to standard PNP/NPN dual discrete level switch with two independent channels.

VIII. Recommended Parameter Set (Food & Beverage Overfill + Low-level Protection Example)

OUT1 (High-level overfill protection): OU1=Hno, SP1=70%, rP1=62%, dS1=0.5s

OUT2 (Low-level empty tank protection): OU2=Hnc, SP2=20%, rP2=15%, dr2=0.5s

FOU1/FOU2=OFF: Both outputs open on fault, triggering safety interlock

IFM LMT102 Hygienic Capacitive Point Level Switch – Engineering Application Cases

Consistent core benefits across all cases: foam / tank deposit suppression, no vibrating mechanical parts, dual-media identification, high-temperature CIP resistance, EHEDG/3-A hygienic certification, IO-Link digitization. 38 mm probe, G1/2 hygienic cone seal, suitable for side or top mounting on small & medium tanks.

Case 1: Brewery Fermentation Vessel (IFM Official Reference Case)

Media: Beer wort, heavy foam, CIP acid / alkaline cleaning fluid

Mounting: LMT102 installed at upper tank top for high-level overfill protection; second LMT102 on lower tank sidewall for empty tank protection

Process Pain Points: Thick foam generated during fermentation triggers constant false alarms with traditional tuning fork level switches. Yeast deposits on tank walls cause frequent false triggering. Need to distinguish beer product from CIP liquid to avoid cross-contamination.

LMT102 Solution

1. OUT1 calibrated for beer, OUT2 calibrated for CIP cleaning liquid; dual-media identification. PLC distinguishes medium type to prevent mixing contamination.
2. Built-in foam and deposit compensation algorithm; foam and yeast deposits do not trigger false signals.
3. Rated for short-term CIP up to 150 ℃. 316L + PEEK + FKM meets hygiene certifications.
4. IO-Link transmits status and fault data. Parameter auto-restore via IO-Link master after sensor replacement, no re-teach-in required on site.

Outcome: Foam false alarms eliminated. No sensor disassembly required during CIP cycles. Reduced product contamination risk. Classic IFM reference case (Skanderborg Bryghus Brewery).

Case 2: Dairy / Oat Milk Mixing Vessel (Similar Danone Projects)

Media: Milk, oat base liquid, dilute sugar solution, CIP alkaline liquid, viscous and prone to wall build-up

Process: Level interlock for mixing tank: high level stops feed pump to prevent overflow; low level stops feed pump to avoid dry running. Strong tank agitation causes heavy liquid surface fluctuation.

Pain Points: Viscous dairy media forms milk fouling on sensors. Agitation causes level fluctuation and signal chatter. Frequent hygienic CIP cycles required.

LMT102 Solution

Upper tank LMT102: OUT1 high-level pump stop interlock; lower tank LMT102: OUT2 low-level empty tank protection

On-site media teach-in enables sensor to compensate for milk fouling and maintain reliable detection with coating on probe

Hygienic cone seal dead-zone free, meets 3-A and EC1935 food contact requirements

LMT series sensors are deployed in batches on Danone oat beverage lines, IO-Link connected to AS-i network for plant-wide diagnostic visibility

Case 3: Sauce / Mayonnaise Mixing Tank (Viscous Water-based Food)

Media: Mayonnaise, salad dressing, tomato paste, high viscosity, prone to probe adhesion

Pain Points: Viscous material sticks to tuning fork prongs and locks the sensor. Strong eddy currents from tank stirring.

LMT102 Solution

1. No vibrating elements; no “stuck” failure caused by material adhesion. PEEK probe with low surface adhesion
2. On-site teach-in calibrates sauce dielectric constant and activates deposit suppression. Reliable liquid / no-liquid discrimination even with thin sauce coating on probe
3. Sidewall mounted for high-level protection. Dual outputs can implement window detection for level range monitoring

Application Note: Works for water-based viscous media as factory preset. Use LMT121 for extremely high sugar / high salt concentrates.

Case 4: Biopharma Preparation Vessel & Buffer Storage Tank (GMP Cleanroom)

Media: WFI water for injection, phosphate buffer, dilute drug solution, CIP cleaning liquid

Process: High / low level interlock for formulation tanks, prevent overflow and pump dry run. CIP/SIP cleaning, strict cleanroom hygiene requirements

Pain Points: GMP requires zero stagnant dead zones. Frequent high-temperature CIP. Fast fault diagnosis required.

LMT102 Solution

1. G1/2 hygienic cone flush mounting, dead-zone free, EHEDG certified for clean fluid service
2. IO-Link real-time diagnostic data enables early prediction of seal ageing and drift, supporting preventive maintenance for pharma plants
3. Dual switch outputs: high-level alarm + low-level empty tank protection. Fault state configurable for safe de-energized interlock

Note: Long-duration SIP steam sterilization (continuous 121 ℃) requires seal evaluation. Short CIP cycles up to 150 ℃ are acceptable.

Case 5: CIP Cleaning Liquid Storage Tank (Acid/Alkali Recovery Tank)

Media: Dilute alkaline cleaner, dilute acid cleaner, water for equipment in-place cleaning in food/pharma

Process: Level control for CIP tank, automatic replenishment of cleaning chemicals, low-level protection for CIP pumps

Pain Points: Corrosion risk from acid/alkaline media; foam generation; need to differentiate clean water and chemical cleaner

LMT102 Solution

316L wetted body and FKM fluororubber seals resistant to dilute acids and alkalis

Dual-media teach-in: calibrate clean water and alkaline cleaner. Two outputs distinguish residual cleaning liquid versus plain water

Foam suppression, no false triggering from foamy cleaning solutions

Case 6: Fruit Juice / Beverage Concentrate Transfer Tank

Media: Fruit juice concentrate, dilute high-fructose syrup, easy foaming and sugar fouling

Pain Points: Heavy foam generated during filling; sugar deposits coat probe and cause drift on conventional capacitive switches

LMT102 Solution

Tank top mounted LMT102 for overflow protection; sidewall low-position sensor for empty tank protection

On-site media teach-in compensates sugar fouling; foam does not trigger false signals

IO-Link remote parameter read/write, batch parameter configuration for multiple production lines

General Selection & Installation Guidelines (Reusable for Projects)

1. Media boundary: Only for water-based media. Pure oil and powder applications are not suitable for LMT102; select LMT110 instead. Use LMT121 for high-sugar / high-salt concentrates.
2. Mounting: Must use IFM matched hygienic welding adapter for G1/2 cone seal. Do not use standard gaskets, which create hygienic dead zones.
3. Probe length selection: LMT102 with 38 mm probe recommended for sidewall installation. Use LMT104 (153 mm) for long insertion from tank top.
4. Comparison with tuning fork: Prefer LMT102 for foamy or build-up prone media. Tuning fork LMT202 is better for non-foamy high-viscosity oil media.

Typical System Bill of Materials (Directly usable for proposals)

Sensor: LMT102

Hygienic welding adapter: IFM G1/2 hygienic adapter

Cable: M12 4-core shielded cable

IO-Link Master: AL1102 / AL1103, connected to Siemens S7-1200/1500 PLC

Software: moneo configure for media calibration and IO-Link parameter backup