Top Mounted Float Operated Level Transmitter Principle of Operation Make level transmitter works on the principle of reed resistance/permanent magnet basis. Reed-switches function like the center arm 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/sq.cm and Temperature 125 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.
Reedswitches 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 oC. to 125 oC.
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.
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.