Dual converters consist of two converters or bridges. One bridge acts as a rectifier and other acts as inverter. Single-phase full converters allow only two-quadrant operations. In full-controlled converter the output voltage is reversible so the converters operate in first and fourth quadrant. The direction of load current remains same. If two full-controlled converters are connected back-to-back then a four-quadrant operation are possible and such type of converters are called dual converters. It is used in high power variable speed drives. Dual converter is operated with either circulating current or without circulating current. When both the converters conduct at the same time, there would be circulating current and the level of circulating current is restricted by provision of an inductor. It is possible to operate only one converter at any instant, but switching from one converter to the other is carried out after a small delay.

Dual Pressure Gauge is designed to use in cars, motorcycles, planes, boats and even machineries. They have a choice of backlit illumination user switchable.

Dual Probe Level Transmitters is designed to measure level of corrosive liquids in non-metallic as well as metallic tanks. The probe measures level by measuring the change in capacitance as level changes in the tank. The application includes pharmaceutical plants, waste treatment plants, water storage tanks, chemical holding tanks and food & beverage industry.

A dual range differential current switch including a differential switch pair of transistors having first and second complementary control inputs which receive first and second complementary signals so as to be controlled by a control signal with equal delay from a clock signal. A first set of switching transistors is coupled to provide the first complementary signal which controls the first complementary control input of the differential switch pair. A second set of switching transistors is coupled to provide the second complementary signal which controls the second complementary control input of the differential switch pair. First delay transistor pairs are coupled to the complementary outputs of the cross coupled inverter and have the characteristic that the fall times of its outputs are greater than the rise time of its outputs. Second delay transistor pairs are coupled to the first delay transistor pairs and have the characteristic that the rise times of its outputs are greater than the fall times of its outputs. The second delay transistor pairs are coupled to the first and second sets of switching transistors such that a first output of the second delay transistor pairs provides a first input signal to the first set of switching transistor pairs and a second input signal of the second set of switching transistor pairs, and a second output of the second delay transistor pairs provides the second input signal to the first set of switching transistor pairs and the first input signal of the second set of switching transistor pairs

A dual-range pressure switch apparatus has a piston member disposed in a switch mechanism containing chamber sealingly pertitioned by a diaphragm in the inner space of a housing, and being movable in the axial direction of chamber. A high-pressure snap disk is placed on the side surface of piston and contacts the diaphragm. In the chamber, a low-pressure snap disk is so arranged that its outer rim engages with the inner periphery of chamber and sandwich the piston between its center and the diaghragm. When the pressure of a pressurized fluid introduced in the inner space is lower than the lower limit of a certain range of values, both low and high snap disks are stable, so that paired resilient switch pieces disposed adjacent to the low snap disk in the chamber separate from each other. When the pressure is set in the certain range, only the low snap disk is transformed to push one switch piece to make it contact the other. When the pressure becomes higher than the upper limit of certain range, the high snap disk is then transformed to push a rod inserted through the piston and the low snap disk, so that the other switch piece is separated from the former transformed one switch piece.

A dual range vacuum switch in which the diaphragm movement with increasing vacuum is opposed by two springs which determine the vacuum required to actuate the switch. As the vacuum subsequently decreases one of the springs is rendered inoperative before the switch resets so the reset vacuum is determined by the one spring remaining effective. The spring which is rendered inoperative is compressed between the actuator and an eyelet which can seat on the actuator (spring ineffective) or the housing (spring effective) and which also functions to limit motion of the actuator relative to the eyelet so the switch operated by the actuator cannot be overstressed.

Dual Scale Dial Calipers separates inch and metric scales and it has fine line indicating hands, easy to read black for inch and red for metric. With this scales we can measure four measurements inside, outside, depth and step. Measuring surfaces are precision ground and lapped.

Dual-channel gas monitor is a compact and highly versatile system for continuously monitoring combustible gas concentrations in two locations. The system consists of two remote catalytic sensing assemblies and a solid-state controller. The controller automatically displays the higher reading channel on a digital display.

Duplex pump panels are specifically designed for outdoor installation. These panels provide full-voltage control of squirrel-cage pump motors. These are used to control two motor driven pumps on a single system. These automatically alternate motor operation under normal demand.

Durometer is one of several ways to indicate the hardness of a material, defined as the material's resistance to permanent indentation. The term durometer is often used to refer to the measurement, as well as the instrument itself. Durometer is typically used as a measure of hardness in polymers, elastomers and rubbers. There are several scales of durometer, used for materials with different properties. The two most common scales, using slightly different measurement systems, are the A and D scales. The A scale is for softer plastics, while the D scale is for harder ones.

Durometers are designed to measure the indentation hardness of materials such as hard rubber, plastics and epoxies. Durometers are used with a test stand or as hand-held testers. Durometers come standard with an ancillary hand for indicating peak readings.

Dust monitor is an instrument designed for on-the-spot measurements of mass concentrations of the respirable fraction of total mass loading of dust particles. It is fully self-contained monitor with automatic and direct digital readout of the mass concentration of airborne dust. It utilizes a two-stage collection system.

Dynamic balancing machine is used to dynamically measure and correct machine/ component balance. It distributes the weight of a rotating body evenly around the axis of rotation, reducing vibration and reducing wear. Three types of balancing machine are available such as static balancing stands, hard bearing balancing machines, and soft bearing balancing machines. It plays an important role in noise, vibration, and harshness analysis in vehicles.

Dynamic Pressure Transducers is used for dynamic & high frequency pressure measurements. Its is ideal for monitoring explosion or pulsation pressures. It features 1-micro-second rise time, welded flush diaphragm, pressure ranges up to 5000 psi, high-level 5-volt output and high frequency acceleration.

Eddy Current Probe Systems are made up of a coil, embedded in the tip of the probe, a separate driver unit and an interconnecting `tuned' length of cable. It depends upon the eddy currents set up in the surface of the target material.

Eddy-Current Proximity Probes are capable of sensing displacement or distance in rotating & reciprocating equipment. The eddy-current proximity probe detects changes in the magnetic flux density field generated by the presence of a metal target. Eddy-current proximity probes are used in turbo machinery evaluation testing and operation to measure distances. It is used for the shaft measurements.

Eight-input temperature transmitter with foundation fieldbus is used to measure temperature. It accepts eight independently configurable RTD, thermocouple, ohm, and millivolt inputs. It is field hardened, intrinsically safe and consumes low power. It reduces the effects of electromagnetic interference. It is easily integrates existing analog instrumentation into foundation fieldbus environment.

Elastometers provides a unique balance of chemical and mechanical properties required for demanding applications.