Top Mounted Float Operated Level Transmitter

Principle of Operation :

Mahalaxmi make level transmitter works on the principle of reed resistance/permanent magnet basis. Reedswitches function like the center arm (as shown in fig. 1) of a potentiometer. As per liquid level float moves up or down, magnet inside the float operates the reedswitches thereby causing a change in resistance value. Change in the resistance is measured by the electronics unit and conditioned as a current output of 4 to 20 mA. Signal conditioner is head mounted and of 2-wire loop powered suitable for 12 to 24 VDC giving output of 4 to 20 mA.

Technical Specification : Our Standard Product

Model (VMT-04-F65-AW) , (VMT-04-F92-AW) top mounted magnetic reed/resistance cascade type loop powered 2 wire level transmitter. Process Connection flange 78 or 120 mm diameter with 4 bolt holes of 6mm or 14 mm dia on 65 or 92 mm PCD respectively. Wetted parts flange & float stopper in SS 304. Float material SS 316L and diameter 41, 53 or 68 mm. Operating pressure 10kg/ and Temperature 125 deg.C. maximum.

Specific Gravity Suitable Down to 0.7 (Upto 0.5 optional)
Range 0-150 mm upto 0-3000 mm.
Resolution Betterthan ±10 mm.
Span Suppression Max. 25% of Span
Zero Elevation Max. 25% of Span
Excitation Voltage 12 - 36 V DC
Loop Resistance Max. 600 OHMs.

Salient Features :

  • Reed switches are hermetically sealed-in glass under an inert gas and therefore protected from contamination.
  • Reedswitches used by us are suitable for maximum working voltage of 150 VDC and current 1 Ampere. But in our circuitry they are subjected to maximum of 3 VDC and current 1 mA in case of resistance output and maximum of 24 VDC and 20 mA when used in conjunction with a signal conditioner for current output. This ensures long life of the product.
  • Reedswitches are UL approved and ISO certified for quality management.
  • Operating temperature range of reedswitches are -40 deg. C. to 125 deg. C.
  • Reed Switches are enclosed in a moulded glass filled nylon capsule and therefore protected from mechanical shocks or damage. Moreover the stainless steel float-guide pipe, containing the PCB of reedswitches and resistances, is solidly filled with MgO Powder. Hence this is suitable for sub zero temperatures.
  • Reedswitches are protected against mechanical damage and contact corrosion & vibration.
  • Since an outer protection tube is provided (for applications like LPG, where external cage is not possible) the reedswitch sensor assembly can be replaced without disturbing the process.
  • Since the float is of 200mm dia with specific gravity -0.4 (for LPG) it will have higher buoyant force. For standard applications float shall be of 48 mm Or 68 mm in diameter.
  • Above all float is the only moving part. No wear and tear.

Application :

  • Applicable in environment with high temp., high pressure, strong acid, strong alkaline and hazardous locations.
  • Multiple applications for textile dyeing, sewage water processing, power generating, boiler and petrochemical industries.