Product

SLM - Solid Level Switches

SLM vibrating fork level switch series are point-level switches for free flowing solids, granules and powders. These are available with explosion-proof housings for hazardous areas.

Note: This product is deprecated. ­ Please refer to next generation product, ‘Vital’.

Measuring System for SLM Vibrating Fork Level Switch

The fork is either side or top mounted on the vessel. Two basic types of constructional arrangements are available. In one, the electronics is separated from the fork, whereas in the other, it is integrated. Mounting arrangements of screwed or flanged type, high temperature models up to 200°C and flameproof versions for hazardous areas are available. Longer probe lengths require pipe extension made of GI or SS. Integral version meant for higher temperature operations are provided with stand­off arrangement for keeping the electronics in a relatively cooler environment. Adjustable probe length is provided with gland arrangement.

The following diagram shows the mounting arrangement of SLM vibrating fork level switch.

 

SLM vibrating fork level switch series are point-level switches for free flowing solids, granules and powders. These are available with explosion-proof housings for hazardous areas.

 

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Principle

A specially shaped tuning fork is kept vibrating using piezo-electric elements. The oscillation of the fork damps when in contact with the material. The loss of oscillation amplitude is detected and used for switching a relay. The output contacts of the relay are in turn used for annunciation or control.

Features
  • Power Consumption: Less than 05 VA
  • ­Power Supply: 24V DC, Universal (90-260 V AC)
  • High temperature durability (H2 – up to 200°C )
  • Independent of material’s electrical properties
  • Suitable for detection of underwater chips
Mechanical Specifications

Resonant Frequency

  •  85 Hz

Probe Length

  • Extensible probe length from 155 mm up to 3000 mm

Enclosure

  • W: Weatherproof
  • P5: IP-65 Weatherproof housing
  • FA: Flame-proof for Gas Groups IIA and IIB

Model

  • Integral version (Electronics Integral with fork)
  • Split version (Electronic separated by a special cable)
  • Separate version (Electronics separated by ordinary 03 core cable)

Process Connection(Mounting Arrangement)

  • Threaded Mounting: 1-1/2”, 2” BSP/NPT
  • Flanged Mounting: As per specification
  • Tri-Clover (as per specifications)
  • SMS union coupling type

Extension Length

  • Pipe- GI/SS: 155 mm – 3000 mm

Probe Length

  • Extension Length + Fork Length (155mm / 185mm / 250mm)

Wetted Parts and Mounting Material

  • S4: SS-304
  • S6: SS-316
  • SL: SS 316L
  • PT: PTFE Lined
  • HL: Halar Lined
  • HC: Hastelloy C

Process Temperature

  • A (Ambient) below 80°C
  • H1 (High temperature) up to 150°C
  • H2 (High temperature) up to 200°C
Electrical Specifications

Input power supply & Outputs

  • SLM 130/120/110: Single SPDT with (90 – 260 V AC) / 230 V AC / 24 V DC
  • SLM 130/120/110: One open collector PNP transistor with 24 V DC
  • SLM 230/220/210: Double SPDT with (90 – 260 V AC) / 230 V AC  / 24 V DC
  • SLM 330/320/310: Single SPDT & Time Delay with (90 – 260 V AC) / 230 V AC / 24 V DC
  • SLM 630/620/610: Double SPDT & Time Delay with (90 – 260 V AC) / 230 V AC / 24 V DC

Power Consumption

  • 05 VA

Fail-safe Setting

  • Field selectable (through toggle switch)
  • Open: Fail-safe High, Close: Fail-safe Low

Response Time

  • 02 – 05 Sec

Time Delay Settings

  • Cover and Uncover Delay: 02s to 20s, through toggle switches

Sensitivity Setting

  • Field Selectable (through toggle switches)
Applications Specifications

Application Material

For all Industries requiring level limit detection in Free Flowing solids including:

  • Powders, sand, sugar
  • Pulverized coal
  • Food grains
  • Cement
  • Granular material
Certifications
  • Flame Proof Housing IIa / IIb certified by CMRI, Dhanbad
  • CE certification
  • IP-65 from ETDC Indore
  • ISI mark from the Bureau of Indian Standards.
Switching Indication
  • 2 LED’s
  • Red: Alarm, Green: Normal