D. B. Instruments & Controls Dahisar, Mumbai, Maharashtra

SALIENT FEATURES : SensComp, Inc. sensor module from U.S.A Over Voltage Protection Reverse Polarity Protection. Direct or Reverse Action Adjustable at site. Output : 0-5 Volts, 0-10 Volts - 3 Wire System. Optional : 4 to 20 mA Output ( as a separate unit). Teach-in Push Button Facility for Minimum & Maximum Value Settings. Stainless Steel AISI 304 Housing Suitable for Outdoor Application. Narrow Beam (15 deg) Angle. 50 Khz Electronic Transducer with Integrated SMT Electronic Circuitry. Range from 1-inch to 12-inch, 6-inch to 20 feet or 12 inch to 40-feet. Power Requirements : 8 to 24 VDC for 5V Output / 12 to 24 VDC for 10 V Output (Maximum Current = 30 mA) Operating Temperature -4 to +85 C (-40 to 185 F)

Since the signals generated by thermocouples or resistance sensors are low on emf and resistance, they can be transmitted over a short distance using compensating and three wire cables, without the loss of signal strength and accuracy. However, to transmit signals over very long distance without loss of accuracy, Two Wire loop transmitters are widely used. The low level signal converted to 4-20mA current output can be transmitted over long distance using a pair of normal copperwire. Accuracy of output current shall be independent of the lead resistance and length of the cable. The transmitter, fits directly into standard terminal head both weather proof or Ex-proof. APPLICATION : For converting thermocouple or Pt-100 or resistance signal to equivalent 4-20mA signal for long distance transmission.

Utilising the basic principle of - liquids find their level - tubular level gauges have been the most preferred and economical means of direct liquid level indication since time immemorial. Various means of glass tube protections- 3 plate glass protection, 3 guard rods, pipe guard or C-channel protections are in popular use. Our level gauges have C-channel protection of 2 mm thick sheet metal, making it robust and sturdy. A black powder coated aluminium engraved scale with white numerals & markings is provided for indication of the level of liquid in millimeter or Litres as required. Scale shall have minimum graduation of 5 mm. Process connections can be threaded or flanged to customer specifications. Isolating cock valves/needle valves or isolating needle valves with safety ball-check protection to prevent spilling/leakage by automatic shut-off in the event of glass tube breakage- are optional features   OPTIONAL ACCEESSORIES : Vent Cock Valve/Drain Cock/Vent & Drain Needle/Ball Valves Gauge Isolating Needle Valves. Gauge isolator valve: SS 304/316 solid barstock needle valve,offset type with safety ball-check protection and process connection as above (please specify).

PRINCIPLE OF OPERATION : 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/sq.cm and Temperature 125 deg.C. maximum. SALIENT FEATURES : 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 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.

FEATURES : The instrument consists of a microswitch inside a cast aluminium box, covered by a flexible membrane of neoprene or silicon rubber. OPERATION : The device must be mounted so that the flexible membrane is exposed to the product whose level should be controlled in such a way that the product, if present, can press the membrane. When this membrane becomes covered up by the product, it moves under the product pressure, thereby working the microswitch. The device must be connected to control signal or to mechanisms driving the product transportation systems, like feeding, unloading ,etc. APPLICATION : Switch has a buoyancy which guarantees smooth, trouble-free operation under all conditions. The switch has double chamber and a final remoulding finish to make it absolutely hermetic. INSTALLATION : MODEL DLS-AL-ND (with neoprene diaphragm) or DLS-AL-SD (with silicon rubber diaphragm) level switch is used for indicating, controlling, and regulating the level of granulated or powdered dry materials with a grain diameter up to 30mm and a density of 0.3 to 2.5 g/cm3, flowing through a silo, hopper or conduit. INSTRUCTIONS AND MOUNTING : The device can be installed outside the container by making a hole on the wall, so that the membrane remains exposed to the product inside. Suspended by means of a tube, it can be also installed inside the container. Using adaptors, it can be installed in pipes and conduits. Wherever possible level switch should be mounted on vertical surfaces. By this means ,the product can flow freely downwards, and wrong indications are avoided. It can be mounted on surfaces with a slope of not more than 30degrees from vertical, provided that the product leaves the membrane thoroughly free when flowing along. If maximum levels are to be controlled, the devices must be mounted at such a height that the product overflowing the membrane can exert pressure on this membrane, working the microswitch.

Magnetic level gauge consists of a float chamber, a float and an external indicator assembly. The float chamber is basically a column of 2" or 2.1/2" NB pipe with process connection to suit that of storage ta nk. The float moves up and down inside the float chamber as per the liquid level. Contained inside the float is a very strong and powerful ring magnet. Follower Type : A borosilicate indicator glass tube and scale assembly is attached to the outside of the float chamber. Inside the glass tube is a red coloured indicator containing a magnet. When the float moves up or down, due to magnetic coupling the red colour indicator also moves along with that indicating the liquid level. The Roller Type : indicator consists of a series of magnets which are coloured red on one side and white on the other side. As the magnetic float passes the magnets rotate through 180 degrees to show the other colour-red indicating liquid space and white vapour. Non-Invasive Switches : In this case the electric contacts are actuated by the magnetic float when it moves as per liquid level. These switches provide a low cost, reliable alarm and control action without making additional cut-outs in the vessel. The externally adjustable mounting arrangement make it easy to adjust the set point or service the switch anytime without interrupting the process. SALIENT FEATURES : No Power Consumption . Will not be affected by power failure. A level transmitter or magnetic switch can be installed and adjusted without disturbing the process. 360 degree magnetic-flux field provides constant interaction with roller assembly in turbulent liquids. Roller channel and outer housing is of black powder coated aluminium. Outer housing in stainless steel as optional. Rollers are of glass filled Nylon / ABS plastic. Rollers move on Delrin bush bearings. Delrin is a self lubricating type material and hence movement will be frictionless, thus ensuring long life. Front window is of crystal clear acrylic. Acrylic windows has a U-gasket i.e. double gasket-gasket on top & bottom side ensuring perfect sealing on both side. Compact, rugged and field proven. In our level gauges the primary magnet attached to float is 360 degree rare earth. Rare Earth magnet has an unusually high energy output and is highly resistant to demagnetization, they will not demagnetize at high temperatures like ceramic magnets. 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.

Usage : Industrial use

Specialities : Rust Proof, High Tensile, Heat Resistance

Certification : ISO 9001:2008 Certified

Mounting Options : New

AC & DC Voltage : 240 VAC

Surface Finishing : Power Coated

Electronic control unit in conjunction with level switches can be used for pump control, opening and closing of electrically operated valves, heaters and or high and low level indication. The electronic unit Model LC1 FL reduces the voltage and converts it to 5 VDC for operation of reedswitches enhancing their life, above all ensuring operational safety. The LED's in the front panel indicates Main Power Supply On, Pump Start and Stop conditions. The start/stop push buttons in the front panel enables testing of the control unit and also manual start and stop. The control unit has a Change over potential free relay output contact-hold on type. Contact change over takes place between High and Low level only. Relay contacts are rated 5 Amps at 230 VAC. Control action can be reversed at site by changing connections from NC to NO. For certain applications where high and low level indications are required, 2 separate relay output contacts are provided in the control unit-with LED indications for High, Low and Mains on Model LC2FL are used in boilers where High and Low Level Contacts are used for Pump start & stop while Very Low Level Contact is used for heater cut off.

Model MLS - 04 / MLS -16 magnetic level switches work on the principle of magnetic repulsion and therefore they are glandless and leak proof instruments. A permanent magnet fitted in the tail piece of the float repels another magnet inside the switch housing which in turn operates an SPDT microswitch. Microswitch contacts can be utilized for initiating audio-visual signals or pump control. SALIENT FEATURES : As our switches work on magnetic repulsion principle, they are glandless and leak proof. No power consumption. Internal assembly wirings are teflon insulated. Internal switch assembly bracket is of cast aluminium. Practically no maintenance is required except periodic cleaning. Suitable for 2.5" (65 mm) NB nozzle mounting, (for 63 mm dia float) and 2 " (51 MM) NB nozzle for 48 mm dia float. Maximum working temperature 250°C. (Process Temperature) Contact ratings of MICROSWITCH 5 AMPS at 230 VAC Resistive. Also available with Microswitich having current rating 10 A at 230 VAC Resistive. No of contacts : 1 change over as standard. Optional - 2 change over For high temperature upto 350°C (Process temperature) 1 number SPDT Reed switch with current rating 100 VA, max. switching current 5 Amps, max, switching voltage 230 VAC / 200 VDC Specific Gravity : Down to 0.75 CAUTION : Level Switches should not be used for direct starting / stopping of pumps. An external relay or contractor must always be used with the level switch. MLS-04/MLS-16 side mounted level switches must always be mounted horizontally with outgoing cable entry facing downwards. In case of high temperature Model MLS-04-92 HT/MLS-16-92HT and Low Temperature Models SMT-04-F82 and SMT-04-F92 arc suppressors/current limiting bias resistor must be provided depending on the load viz inductive or lamp load etc. to reduce the deteriorating effect of contacts due to surge voltages and high in-rush current TECHNICAL SPECIFICATION : Model (MLS-04-F82) or (MLS-04-F92S) side mounted magnetic Level Switch.Process connection- 82 or 92mm square flange with 4 bolt holes of 10/14mm dia on 82 or 92mm PCD respectively. Matenal of construction of flange, brackets, fulcrum screws, body and cover-SS 304(For wetted parts in SS 316 please denote by 16 instead of 04 in the Model). SS 316L float. 1 no SPDT microswitch having current rating 5 Amps at 230 VAC resistive. Differential between make and break-10mm approximately.Maximum working pressure 10 kg/sq.cm and temperature 250 deg C.Specific gravity down to 0.7.Cable entry neoprene gromet. Supplied with 1.5 Metre long 3-core PVC Cable. NB : In case of Model MLS-04-F92 flange size shall be 120 mm dia round flange with 4 bolt holes of 14 mm on 92 PCD. .  

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. TECHNICAL SPECIFICATION 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. SALIENT FEATURES : Two parts isolated design-Electronic Module can be easily separated without removing the probe and without necessity of process shut down. So module replacement is easy. No moving parts, it is rugged and robust instrument. No dead band or dead zone like float based/ultrasonic instruments Suitable for operation from 12 to 32 VDC, with reverse polarity protection. Standard output 4-20mA.Voltage output of 0-10 optional. (For 12 V input supply output 0-5V and with 24 V supply output 0-10V) Plug and play with reference probe and rod. Remote electronics as option with 2 Metre long coaxial cable. Standard enclosure weather proof-cast Aluminium or Nylon 66. Flame proof as optional. Trim-Pots for span and zero adjustment. Kitchen & Hospital Equipments, etc.

Cable float switch is a control device for filling and discharging pumps, motor and magnetic valves. It is also an alarm device at certain pre-determined surface levels. It is suitable for use in non-flammable liquids at 250 volts. In dangerous enviroments (e.g. wells and pumping stations) we recommend 24 V voltage. In potentially explosive atmospheres (e.g. oil tanks) the Switch can be used in conjunction with (Ex) i-isolator switch units. Due to its large float casing the float Switch has a buoyancy which guarantees smooth, trouble-free operation under all conditions. The switch has double chamber and a final remoulding finish to make it absolutely hermetic. INSTALLATION : Cable Float Switch is simply placed in the liquid so that the float follows the movement of the surface. The switching height differential is adjusted by moving the weight along the cable. The differential is minimum, when weight is nearest to the float. If the viscosity of the liquid is high, we recommend an extra weight on the cable.