HD404T - HD404ST , HD404T - HD404ST Detal Ohm , HD404T - HD404ST Detal Ohm Vietnam

 

HD404T - HD404ST , HD404T - HD404ST Detal Ohm , HD404T - HD404ST Detal Ohm Vietnam
GHM Group, GHM Group Vietnam, 
Dai Ly Detal Ohm, Dai Ly Detal Ohm Vietnam, Detal Ohm, Detal Ohm Viet Nam, Detal Ohm Vietnam

The series of HD404T transmitters is able to measure relative pressures with reference

to the atmosphere or differential in the range:t from 50 to 1000 Pa (from 0.2” H2O to 4” H2O) for the versions with analog output;

t

250 Pa / 1000 Pa / 100 mbar for the versions with RS485 Modbus-RTU output.

HD404T transmitters use a silicon “micro-machined” type sensor compensated in

temperature that has an excellent linearity, repeatability and stability over time.

The output signal from the sensor is amplified and converted, depending on the model,

into a standard current analog output (4-20 mA) and a voltage analog output (0-10 V),

or into a digital RS485 Modbus-RTU output, which, then, can be transmitted over long

distances with a high immunity to noise.

In the models with analog output it is possible to choose, via a dip switch, between two

measurement ranges in order to select the optimal scale for each application.

Usually the low pressure transmitters are susceptible to the guidance by which they

are mounted. In HD404T series there is available a special auto-zero circuit, which

periodically equalize the differential pressure at the input sensor and corrects the

offset; the transmitters, provided with this circuit, are insensitive to the mounting

position. In addition, the circuit compensates auto-zero aging and the deviation of the

zero of the sensor to temperature changes: virtually eliminates maintenance.

It’s available the (L) “display” option, in which the pressure is visualized on a display

with 4 digits in the selected measurement unit.

The (SR) “square root” is especially useful if the transmitter is connected to a Pitot

or Darcy tube, as the output is directly proportional to the speed of airflow. The SR

version with L option also allows to display, in addition to the pressure measured, the

speed of airflow calculated. The SR version is configurable by the user by connecting

the transmitter to a PC and sending serial commands via a standard communication

software. It is possible to set the coefficient of the Pitot or Darcy tube used and the

parameters for the calculation of the speed (airflow temperature, barometric pressure,

differential static pressure in the duct). In the models with analog output it is possible

to set the speed unit of measurement (m/s or ft/s) and the speed full scale for the

analog output. In the models with RS485 Modbus-RTU output it is possible to read the

measures in different units of measurement.

The transmitters are ready to use and are supplied calibrated by the manufacturer.

Typical applications for HD404T series are clean room monitoring, filters’ control, flow

measures (matched with the Pitot tube), the air conditioning control and the ventilation

one