Dear all

We have a DT800 since many years and we use it a few times for temperature measurings
Now, i have a new chalenge to build a weather station with some sensores the we have in the lab

The sensors are:

SP Lite2 Pyranometer; sensitivity 68 uV/W.m-2
Thies anemometer 0.5-40m/s, a T351-TR Thermistor, a very old pluviometer that I will calibrate it.
And some k thermocouples for surface temp.
I will need to buy a humidity sensor (suggestions are well come)

I had worked with DT800 some years ago with DLogger.
I tested a few days and evrything works fine.

My message in forum is because I do not understand nothing about wetaher stations.

The requirements: "max-min and cumulative temp; max and cumulative solar radiation; number of hours of sunlight per day; humidity; max min precipitation, wind speed"

I read here that some people has donne it very weel.

I will appreciate that I some one can help me configure it throught DLogger.

For starting I am now working with the pyranometer I configure it to read voltage and after conecting, I get some reading in mV and it changes values with or without sun light, next step how to configure it to get units?

best
cpalha

Dear All

Yesterday I configured the pyranometer channel as a voltage and it measures about 30 mVolts inside the room
Outside in sunlight is gives about 100mV
After that I configure another channel as CV with a formula from pyranometer channel. The formula is in the datasheet
Esolar (W/m2)=Uemf(uV)/S(uV/W/m2)

Seems it works fine I need to multiply mV*1000 to get uV

About the temperature sensor, thermistor T351-TR from Vector, 2Kohms at 25ºC, the DLogger has no possibility to configure it as 2000 ohms, but near with YS04 I get near temp values.

Now is the wind speed sensor, small wind transmitter, 1 pulse/revolution.
Can someone tell me what type config I need to config it in DLogger? I try with counter, but no values. Frequency does not work too. As analog input it changes between 0 and 1. How can I add a formula to change it for m/s?

Best regards
Cpalha

Dear all

I am sorry for insist but I need help how to config a wind speed (1 pulse/rev)
I config it as a counter and it count pulses, but how to convert to speed m/s
I know that the wind speed has the 0.8m/rev as constant.

Best regards
Carlos

Hi cpalha,

We apologize for the late response.

Let us start to solve the pyranometer, as you can get the reading you should be able to set up the scaling. In DeLogger at the bottom of your configuration screen, you will see the schedules tab.

At the end of the schedule tab, you will find the scaling. Please set the scaling to linear and provide the numbers, physical means the output (W/M2), and the signal means the voltage output from the sensor (mV or uV).

As the sensor does not provide you with a clear voltage output range but only the sensitivity, you will need to calculate the maximum voltage output based on the sensor's maximum reading range. Example 68 uV/W/m2 with a maximum of 2000 W/m2, meaning the voltage output would be 0 mV - 136 mV.

You can use that range for your scaling. Or there is a second option in which you divide the reading with 68 uV (or 0.068 mV) to get the W/m2 reading. Remember division means multiplication in another way, which basically you can multiply the reading with 14.7 (1/0.068). Please use a polynomial and set 14.7 on the second column (the label is incorrect) and leave the other column with 0.

Next is the wind speed, you need to read the output pulses from the sensor. You need to read it as a counter, then enable some option to get the frequency. The first option would be the "reset", click the wiring's triple dots and enable the option. The second option would be data manipulation "Reading/ time difference (RS), this will allow getting the reading per second (frequency).

After getting the frequency you can enable another scaling to convert it to m/s.

Best regards,
dataTaker Expert

Dear sir

Many thanks for the help.
I will try the tips. In fact the weather station starts working a few days ago.

Rainflow and wind only get the pulse counts....
I read in the manual that DT800 has the RAINFLOW chanel but a could not discovery it yet (I use dlogger)

Other thing is that I have a chanel for reading voltages and then creat another one (CV) for scaling it.
How can I not save the voltage chanel in data file and only save the CV chanel?

Sample interval 15min...
Wind sensor: 0.8m wind run, range 0.5 to 40m/s
Pyrometer: 69.8 uV/Wm2 (I use the Irrad=outputV/Sensitivity)
Pluviometer: 0.2mm/tip

I would be really thank you I you could help me improve the code

'JOB=JOB1
'COMPILED=2023/08/04 11:06:54
'deLogger generated program file for dataTaker 8 series
DT=\d
BEGIN"JOB1"
CATTN
'Spans and polynomial declarations
S1=0,1,-40,60"ºC"
S2=0,1,0,100"%H"
'Thermistor declarations
'Switches declarations

'Parameter declarations
P31=3
P47=10
'Global declarations
RS1S
'main schedule definitions

'schedule definition
RA15M LOGONA  GA
1TK("Tempk1")
1*TK("Tempk2")
2TK("Tempk3grosso")
2*TK("Tempk4metal")
4V("pyramV",=6CV)
6CV("Rad (W/m2)")=6CV*1000/69.8
5YS04(2W,"therm")
1C("pluvi",=9CV)
9CV("pluvi (mm)")=9CV*0.202
2C("wind",=2CV)
6V("TempH",=7CV)
6*V("HumT",=8CV)
7CV("Temp_TH (ºC)")=(7CV*0.01)-20
8CV("Hum_TH (RH)")=8CV*0.010
END
'end of program file

Best regards
Carlos Palha

Hi Carlos,

Should you reset the rain counter or keep it counting up?

Then for the humidity, you can declare the multiplication for 8CV as a channel factor, thus the last line can be omitted.

The same with the voltage channel for radiation, in which you can use (1000/69.8)=14.326 as a channel factor.

Notes:
Channel factor is not applicable for the counter channel, so you can't use it for the pluvio.

Best regards,
dataTaker Expert

Hi

In that time I need to measure the rain and the wind correctly and replace the pulses count. Now I have it not reset counts.
I read in the dt800 manual that is has the fuction RAINFLOW but I couldnt discovery it. Seems I need to have A and B programs, A I still use 15min data acquisition and B for example 15ms for wind and then calculate max, min avrg, etc...
Radiation, temps and Humid seems works good but 1 reading each 15min, I will do in excel for a day max min and avrg.

Best regards
Carlos

Hi Carlos,

Rainflow cycle counting is not for rain monitoring but for structural analysis in relation to fatigue stress. We know the name is a bit confusing, you can check the detail in https://en.wikipedia.org/wiki/Rainflow-counting_algorithm.

For rain monitoring, you need to use multiple schedules with different time intervals. For example, if you want to read the pulse every minute then add a counter channel in schedule A. In this counter, assign a CV (i.e.: 1CV) and reset the option. In the same schedule, you need to add another CV (i.e.: 2CV) to sum up the previous CV.

The second schedule will have a longer interval, mostly 1 hour since we know about mm/hour for rain. And the third schedule runs every day. Both the second and third schedules will become a place to call the CV from a faster schedule (for logging purposes) and then reset it.

RA1M
1C(=1CV,R)
2CV(W)=2CV+1CV

RB1H
2CV("Rain~mm/hr")
3CV=3CV+2CV
2CV(W)=0

RC1D
3CV("Rain~mm/day")
3CV(W)=0

Best regards,
dataTaker Expert

Many thanks

And for the wind speed? Can You suggest something?
It has this characteristics

Wind sensor: 0.8m wind run, range 0.5 to 40m/s

Best regards
Carlos