Ammonit Data Logger Manual
16
Ammonit GmbH / 2005 - 2009
2.2. Wind vane
To register the wind direction attach a serial opto-electronic sensor or a wind
vane with a potentiometer, which should have a total resistance of 2000
Ω
-
10 k
Ω
. The potentiometer is addressed ratiometrically, to make allowance for
temperature and cable influences on the measurements. Results are
independent of fluctuating supply voltages and the resistance of the
potentiometers. The resolution of a 2000
Ω
-vane is 1° with a precision of
±
1°
over the entire temperature range. Calibration is not necessary, but may help to
correct for any offset of the wind vane introduced during the installation.
d = U + O
d = Wind direction
U = Measured value
O = Offset (Angular deviation to North)
The measurement values are presented in 1°-steps f rom 1° ... 360°, measured
clockwise:
V
V
a
a
n
n
e
e
1
1
:
:
3
3
4
4
2
2
°
°
Any implausible measurement values are documented as "777".
The directional data is stored in 1 degree steps. Mean values are calculated,
and of course the mean of "1°" and "359°" is record ed as "North (360°)" and not
"180°"!
2.3. Hygro/Thermo
These inputs are only available for the "METEO" versions.
Either a simple temperature sensor (e.g. the "TPC", P6471) or a combined
hygro / temperature sensor (e.g. the "KPC", P6831) can be connected directly to
the "Hygro/Thermo" socket.
The temperature sensor contains a resistance thermometer, and the
measurement is converted by the sensor into a voltage proportional to the
temperature. For the correct evaluation of the measurement signal enter the
gradient and the intercept of the sensor characteristic as parameters.
T = a
·
U - b
T = Temperature
a = Gradient
U = Measured voltage
b = Intercept
The gradient is in °C/V. The temperature reading in °C for 0 V output voltage is
entered as the Intercept value.
Summary of Contents for METEO-32
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Page 47: ...Ammonit Data Logger Manual 46 Ammonit GmbH 2005 2009...
Page 57: ...Ammonit Data Logger Manual 56 Ammonit GmbH 2005 2009...
Page 73: ...Ammonit Data Logger Manual 72 Ammonit GmbH 2005 2009 4 plug Xtend Plan view Data Logger...
