When ive connected the barometer vaisala PBT101B to the CR1000 logger, the actual reading in mbar is 475mbar, while the actual pressure is 1022mbar.(the selected units is set to mbar)
The other issue i have is with the cm3 pyranometer, when it is getting darker, the value rises...
Also when i select the cm3 pyranometer(used together with a amplifier to 0… 2000W/m² @ 4…20mA) in the shortcut programm, the value displays nan. So i use it with the 4-20mA function in shortcut.
* Last updated by: Mavada on 6/3/2010 @ 1:54 PM *
Mavada,
Shortcut is not setup to accommodate the CM3 pyranometer in conjunction with the Amp Box noting Campbell Scientific Inc never re-sold the AmpBox with the CM3 pyranometer. Rather shortcut assumes the output of the CM3 is voltage and creates a program utilizing the 'VoltDiff' instruction to measure the pyranometer. The CM3 pyranometer outputs a raw mV signal. The CR1000 cannot directly measure a 4-20 mA current loop without the use of a current shunt such as the CURS100 [http://www.campbellsci.com/curs100]. I'm curious why you would use the AmpBox when the CR1000 has the capabilities to measure the CM3 pyranometer directly? Although the AmpBox and CURS100 incorporate precision resistors to convert the mV output of the CM3 to a 4-20 mA current loop and back the addition of these components will contribute error to the accuracy of your irradiance measurements. Let me know if I can be of any further assistance regarding this matter?
Okay, i use it with a 124 ohm resistor.
But i can use it without the ampbox? Only usee the current shunt between the h en l and than shortcut will recognize the cm3?
Yes the CR1000 can measure the CM3 directly without the use of a completion resistor or current shunt. Simply un-wire the CM3 from the AmpBox terminal strip and re-wire directly to the CR1000 analog channels as defined by the Short Cut for Windows wiring schematic. For Example: Red to 1H, Blue to 1L, White to Ground, and Clear to Ground.
okay, thank you very much, ive struggled with it so long...
Do you know also a solution for my vaisala pbt101b barometer, wich is displaying a much to low value in mbar, it shows 475 mbar instead of 1022 mbar wich is shown in a weathersite in my hometown...
Did you choose the CS105 from the Shortcut Sensor database?
Yes i used the pbt101b in the uk sensor support and also tried the cs105 inthe us sensor support. Both the same low value...the green on the H the white on the L or G and the red and black are the power supply 12v on the datalogger output section...
I noticed that when i ad a single ended measurement in shortcut the barometer value rises with 10mbar... Strange behaviour... Has the other sensors a influence on the barometer readings?
Problem barometer solved, i just tried another H and L on the CR1000 datalogger and that worked. But it is strange it depends on which high and low the barometer is connected.
Also the CM3 is now connected without the ampbox and current shunt, now it works, i only dont know wich sensitivity to use in the shortcut setup for the CM3...
Mavada,
Each analog channel of the CR1000 datalogger has to be configured to measure a specific sensor. You will see blue (Single Ended) and white (differential) labels above the green terminal strips of the CR1000 wiring panel. The wiring diagram shortcut for windows generates needs to be followed explicitly when wiring up the sensors.
The sensitivity is a calibration specific value to your CM3 pyranometer. This value is printed on the sensor itself. If the label is gone the calibration certificate also displays the value. If you have neither you can contact Kipp and Zonen directly to see if they have the sensitivity value on file.
Justin
The sensitivity on the CM3 displays:
23.09x10-6V/Wm-2
(where the -6 and -2 are smaller displayed)
What does it mean and how to use it in the shortcut sensitivity area? It must be a value between 5 and 70...
So what value to use in order to use the sensitivity mentioned above?
Or is it possible to darken the CM3 and use the sensitivity value to set it to zero...
The sensitivity value is reported in volts per watt per meter squared. Shortcut is asking for micro volts per watt per meter squared. To conver from volts to micro volts you must move the decimal six places. Therefore you enter 23.09 into shortcut for windows.
The darkening technique you mentioned is not valid. It can however be used as a simple test to make sure the sensor is being measured correctly by the CR1000. The sensor should output zero or a slightly negative number when darkened.
Great work!!!!! Everything i needed to know is clear and works great.
THANK YOU VERY MUCH FOR YOUR TIME AND ADVICE!!!!!
With kind regards,
Mark