A capacitance is formed between the probe and the vessel wall .As the level of the measuring medium rises or falls capacitance between the probe and vessel wall changes proportionately. A high frequency sine wave is applied between the probe and tank wall. A change of medium level will induce a change in the current of the applied sine wave. From when the capacitance in the vessel increase, impedance will decrease and current will increase and vice-versa. (Z=Resistance, C=Capacitance, F= Frequency)
Head mounted electronics converts the capacitance variation to 4-20mA signal for long distance transmission. It is provided with trimpots for SPAN and ZERO adjustments. With no moving parts it is free from wear and tear, rugged and robust in construction. No dead zone like float based instruments.
It must be ensured that the probe is parallel to the tank wall throughout it's length.
Mahalaxmi make Capacitance type 3 wire Level transmitter Model (CLT-1) with non insulated probes for non-conductive liquids or PTFE Teflon insulated probes for conductive liquids.
|Frequecy of operation||5 to15kHz.|
|Probe Material||Stainless Steel / Teflon insulated 10/12/16 mm rod upto Max 3 Metre length|
|Process connection||3/4",1",1.1/2" BSP(M) or 1 "ASA 150 lbs flanged but thickness 12mm (or as per customer specification)|
||4 to 20 mA.(non-isolated)|
|Span & Zero adjustment||Trim pots|
|Accuracy||±0.5%, ±1% or ±2%|
|Enclosure||Cast aluminium weather proof with PG9 cable gland or Flame proof (IS2148-2004,Gr II A and B gases)|
|Cable Size||3 core, 0.75 sq.mm screened PVC cable.|
While sending enquiries for capacitance type level transmitters, please furnish following informations to enable us to submit a suitable offer: