GHM Delta OHM HD52.3D Series User manual

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Operating manual
Ultrasonic anemometers
HD52.3D… series
www.deltaohm.com
English
Keep for future reference.
Companies / Brands of GHM

HD52.3D… - 2 - V2.2
TABLE OF CONTENTS
1INTRODUCTION....................................................................................................3
1.1AVAILABLE VERSIONS ..........................................................................................4
2TECHNICAL SPECIFICATIONS...............................................................................5
3DESCRIPTION.......................................................................................................8
4MEASURING PRINCIPLE OF WIND SPEED AND DIRECTION ................................ 10
5INSTALLATION ...................................................................................................11
5.1ALIGNMENT OF THE INSTRUMENT............................................................................ 12
5.2ELECTRICAL CONNECTIONS.................................................................................. 14
5.2.1RS232 SERIAL CONNECTION ...................................................................15
5.2.2RS485 SERIAL CONNECTION ...................................................................15
5.2.3RS422 SERIAL CONNECTION ....................................................................16
5.2.4SDI-12 SERIAL CONNECTION ...................................................................17
5.2.5ANALOG OUTPUTS CONNECTION.................................................................17
5.2.6CONNECTION OF RS52 CABLE...................................................................18
5.2.7CONNECTION OF HEATING SYSTEM ..............................................................18
6CONFIGURATION................................................................................................19
6.1SERIAL COMMANDS...........................................................................................20
7PROPRIETARY RS232 MODE ...............................................................................30
8PROPRIETARY RS485 MODE ...............................................................................31
9NMEA MODE........................................................................................................ 32
10MODBUS-RTU MODE ...........................................................................................34
11SDI-12 MODE...................................................................................................... 37
12INSTRUMENT STORAGE ...................................................................................... 40
13SAFETY INSTRUCTIONS......................................................................................40
14ORDER CODES ....................................................................................................41

HD52.3D… - 3 - V2.2
1INTRODUCTION
The instruments of the seriesHD52.3D… are 2-axis ultrasonic static anemometers. The availa-
ble measurement options combine in a single instrument the main quantities of meteorological
interest, making the instrument like a compact and light meteorological station.
Measured quantities:
Wind speed and direction, U-V Cartesian components of wind speed
Wind Gust
Relative Humidity and temperature (optional)
Global solar radiation (optional)
Barometric pressure (optional)
Rainfall (optional)
The “Rainfall” and “Global solar radiation” options are alternatives (they can not be both pre-
sent in the same instrument).
The average of wind speed and direction over a period configurable up to 10 minutes is calcu-
lated.
All models are equipped with a magnetic compass.
Wind speed and direction are determined by measuring the transit time of ultrasonic pulses
between two pairs of ultrasonic transducers.
RS232, RS485, RS422 and SDI-12 serial interfaces are available with NMEA, MODBUS-RTU
and SDI-12 communication protocols.
All versions have two analog outputs, for wind speed and direction, which are factory-
configurable within 4÷20mA (standard), 0÷1 V, 0÷5 V or 0÷10 V (to be specified when or-
dering).
The heater option prevents the accumulation of snow and ice formation, allowing precise
measurements in all environmental conditions.
Mounting on 40mm mast. The electric connection is performed through a M23 19-pole con-
nector situated on the bottom of the instrument.
The low power consumption of the instrument allows installation in remote sites, with power
supplied by photovoltaic panel and backup battery.
The absence of moving parts minimizes the instrument maintenance.

HD52.3D… - 4 - V2.2
1.1 AVAILABLE VERSIONS
The table below shows the measuring quantities available in the different models of the series:
TAB. 1.A – Available versions
Model Wind
speed Wind direction
Relative
humidity
+
Temperature
Solar
radiation Rainfall Barometric
pressure
HD52.3D 
HD52.3D4 

HD52.3DP 
HD52.3DP4 
HD52.3D17 
HD52.3D147 
HD52.3DP17 
HD52.3DP147 
HD52.3DT147 
All the models, except HD52.3DT147, are available with heating option (add Rat the end of
the code).

HD52.3D… - 5 - V2.2
2TECHNICAL SPECIFICATIONS
Wind speed
Sensor Ultrasounds
Measuring range 0…60 m/s (0…50 m/s with rain gauge option)
Resolution 0.01 m/s
Accuracy ±0.2 m/s or ± 2%, the greatest (0…35m/s), ± 3% (>35 m/s)
Wind direction
Sensor Ultrasounds
Measuring range 0…359.9°
Resolution 0.1°
Accuracy ± 2° RMSE from 1.0 m/s
Compass
Sensor Magnetic
Measuring range 0…360°
Resolution 0.1°
Accuracy ± 1°
Air temperature (needs option 17)
Sensor Pt100
Measuring range -40…+70 °C
Resolution 0.1 °C
Accuracy ± 0.15 °C ± 0.1% of measurement
Relative humidity (needs option 17)
Sensor Capacitive
Measuring range 0…100%RH
Resolution 0.1%
Accuracy (@ T = 15…35 °C) 1.5%RH (0…90%RH), 2%RH (remaining range)
Accuracy (@ T = -40…+70 °C) (1.5 + 1.5% of measurement )%RH
Barometric Pressure (needs option 4)
Sensor Piezoresistive
Measuring range 300…1100 hPa
Resolution 0.1 hPa
Accuracy ± 0.5 hPa @ 20 °C
Solar radiation (needs option P)
Sensor Thermopile
Measuring range 0…2000 W/m2
Resolution 1 W/m2
Accuracy 2nd Class Pyranometer
Rainfall (needs option T)
Sensor Tipping bucket
Resolution 0.2 mm
Accuracy 99% up to 120 mm/h
Maximum rainfall rate 2000 mm/h
Collector area 127 cm2
General features
Power Supply 10…30 Vdc
Power consumption 26 mA @ 24 Vdc without heater
8W @ 24 Vdc with heater
Serial outputs RS232, RS485 (¼ Unit Load), RS422 and SDI-12

HD52.3D… - 6 - V2.2
Communication protocols NMEA, MODBUS-RTU, SDI-12, proprietary RS232 and RS485
Analog outputs 2 analog outputs, for wind speed and direction. Output at
choice among 4…20 mA (standard), 0…1 V, 0…5 V and
0…10V (option 0…10V needs 15…30 Vdc power supply)
Wind speed averaging interval Configurable from 1 s to 10 min
Electrical connection 19-pole M23 male connector
Operating temperature -40…+70 °C
Minimum temperature for the rainfall sensor 1 °C
Protection degree IP 66
Survival speed 90 m/s (60 m/s with rain gauge option)
Weight About 1 kg (version HD52.3DP147)
About 1.5 kg (version HD52.3DT147)
Case Plastic material. Metal parts: AISI 316
Dimensions (mm)
150
336
40 ext.
36 int.
50
150
357
40 ext.
36 int.
50
HD52.3D17 / HD52.3D147 HD52.3DP17 / HD52.3DP147
Mast Mast

HD52.3D… - 7 - V2.2
HD52.3D / HD52.3D4 HD52.3DP / HD52.3DP4
132
547
40 ext.
36 int.
50
150
HD52.3DT147
Mast Mast
Mast

HD52.3D… - 8 - V2.2
3DESCRIPTION
1. Pyranometer
2. Ultrasonic sensors for the measurement of wind speed and direction
3. Protective shield from solar radiation for relative humidity and temperature sensors
4. Fixing clamp to Ø 40mm mast
Note: in the models measuring barometric pressure, the pressure sensor is inside the instru-
ment.

HD52.3D… - 9 - V2.2
Version with rain gauge
1. Rain gauge
2. Ultrasonic sensors for the measurement of wind speed and direction
3. Protective shield from solar radiation for relative humidity and temperature sensors
4. Fixing clamp to Ø 40mm mast

HD52.3D… - 10 - V2.2
4MEASURING PRINCIPLE OF WIND SPEED AND DIRECTION
Wind speed and direction are determined by measuring the time taken by ultrasonic pulses to
cover the distance from the transducer that generates the pulse to the receiving transducer.
The instrument uses 2 pairs of transducers oriented along two orthogonal axes. Detecting the
wind speed along two axes allows determining not only the intensity but also the wind direc-
tion.
The instrument measures the travel time of the ultrasonic pulse between the two transducers
of the same pair in both directions. The travel times in the two opposed directions are defined
as tA(forward direction time) and tR(reverse direction time).
If wind speed is zero, tAand tRvalues are the same. In the presence of wind, one of the two
time values is greater than the other and the comparison between the two time values allows
to determine the direction and the intensity of the wind.
Measuring the travel time in both directions allows to cancel the dependence of the transmis-
sion speed of ultrasounds in the air from the environmental conditions of temperature, humidi-
ty and barometric pressure.
Measurement along first axis Measurement along second axis
The travel times of the ultrasonic pulses are given by:
W
AVC D
t W
RVC D
t 
Where:
D= Distance between the two transducers of the same pair
C= Sound speed
VW= Component of wind speed along the measurement axis
Measuring the two travel times allows determining the wind speed component:





 RA
Wtt
D
V11
2
Axis U
Transducer Transducer
Transducer Transducer
Axis V