Data Sheet

2
[
GB
]
[ GB ] HD402T - HD402ST
Pressure Transmitters
• Sensor with high accuracy and stability
• Measurement of pressures relative to the atmosphere or differential pressures
• Dual analog output, current and voltage, or RS485 Modbus-RTU output
• Versions with or without LCD display
Applications
• Control of air conditioning and ventilation
• Control of filters
• Monitoring of clean rooms
• Pneumatic controls
• Respirators
• Vaporizers
Description
The series of transmitters HD402T... is suitable for measuring relative pressure with
respect to atmosphere or differential pressure in the range from 50 Pa to 200 kPa.
These transmitters use a silicon piezoresistive sensor with high accuracy and
temperature compensation, which has excellent linearity, repeatability and stability
over the time.
The output signal of the sensor is converted, depending on the model, into a
digital RS485 Modbus–RTU output or into a standard analog output to be chosen
between voltage 0...10 V or current 0...20 mA or 4...20 mA. The output signal can
be transmitted over long distances with high immunity to interference (in the models
with analog output the maximum distance depends on the load and the section of the
connection cables, but distances of several hundred meters are commonly reached).
Different units of measurement can be chosen for each model and, in the models with
analog output, it is possible to choose the full scale (f.s.) value for the output (high,
intermediate or low range) and set the unipolar (0 ... +f.s.) or bipolar (-f.s. ... +f.s.)
measuring range.
The configuration can be made through a series of dip switches mounted on the
circuit board or by connecting the serial port of the transmitter to the PC.
Thanks to the particular sensor used, the transmitters are insensitive to orientation
and position. Moreover, the high stability of the sensor over the time and in comparison
to the changes in temperature allows to eliminate the operations of maintenance
typically required to compensate for the aging and the deviation of the sensor zero.
The option “display” (L) is available, in this case the values of pressure are displayed
on a 4-digit display under the unit of measure set by the user.
The transmitters are supplied ready for use and factory calibrated in 3 points.
Power supply: 24Vac or 18...40 Vdc for the models with analog output, 12...30 Vdc for
the models with RS485 Modbus-RTU output.
Technical specifications
Sensor Piezoresistive, High stability
Measuring range from 0…50 Pa to 0…200 kPa both relative and
differential (please refer to table 1)
Resolution Please refer to table 2
Accuracy @ 25 °C ± 1.5% f.s. nominal for HD402T1
± 0.75% f.s. nominal for HD402T2
± 1% f.s. nominal for HD402T3, HD402T4 and HD402T5
Accuracy @ 0…50 °C ± 3% f.s. nominal for HD402T1
± 1% f.s. nominal for HD402T2, HD402T3, HD402T4 and HD402T5
Long term stability
(1000 h) @ 25 °C
± 0.5% f.s. nominal for HD402T1 and HD402T2
± 0.35% f.s. nominal for HD402T3
± 0.25% f.s. nominal for HD402T4 and HD402T5
Output signal • Models with analog output:
0…10 Vdc R
L
> 10 kW and 0…20 or
4…20 mA R
L
< 500 W @ 24 Vdc
• Models with digital output: RS485 Modbus-RTU
Response time Configurable 0.125, 1, 2 or 4 seconds for the output
0.5 seconds for the display updating
Overpressure limit 50 kPa for the models with f.s. up to 10 kPa
200 kPa for the model with f.s. 100 kPa
400 kPa for the model with f.s. 200 kPa
Compatible media Only air and non-aggressive dry gases
Power supply • Models with analog output:
24 Vac ± 10% or 18…40 Vdc
• Models with RS485 Modbus-RTU output:
12…30 Vdc
Absorption • Models with analog output:
< 1 W @ 24 Vdc
• Models with RS485 Modbus-RTU output:
< 100 mW @ 12 Vdc
Pressure connection Ø 5 mm hose
Electrical connections Screw terminal block, max 1.5 mm
2
, PG9 fairlead for
the input cable
Operating conditions -10…+60 °C / 0…95% RH
Storage temperature -20…+70 °C
Housing dimensions 80 x 84 x 44 mm
Protection degree IP67