Flatirons M2 Instrument Descriptions and Histories


Model Measurement
Notes (below)		 Units Install
Date		 Removal
Date		 Current
SN		 Current
CF
PSP Global Horizontal (Ventilated)
& Accumulated Irradiation		 W/m2
kWhr/m2		 09/23/1996 02/01/2021 20517F3 see database (click S/N)
Total Hemispheric shortwave irradiance as measured by an Eppley Laboratory, Inc. Model PSP (Precision Spectral Pyranometer) with calibration factor traceable to the World Radiometric Reference (WRR). The instrument is swapped out (with SN 20517F3 or SN 31555F3) and calibrated annually by NREL at the Solar Radiation Research Laboratory (SRRL). The Accumulated Global Horizontal is also calculated in the datalogger and reset every midnight (standard time). The ventilated PSP is mounted several feet above ground level.
CMP11 Global Horizontal (Ventilated)
& Accumulated Irradiation		 W/m2
kWhr/m2		 06/01/2021 - see database see database (click S/N)
[DQS]
[Maint]		 Total Hemispheric shortwave irradiance as measured by an Kipp & Zonen Model CMP11 Pyranometer with calibration factor traceable to the World Radiometric Reference (WRR). The instrument is swapped out (with SN 163580 or SN 153055) and calibrated annually by NREL at the Solar Radiation Research Laboratory (SRRL). The Accumulated Global Horizontal is also calculated in the datalogger and reset every midnight (standard time). The ventilated CMP11 is mounted several feet above ground level on a 2AP Solar Tracker (unshaded).
SS-201 Wind Speed m/s 09/23/1996 - see database see database (click S/N)
[DQS]
[Maint]		 The mean wind speed at 80, 50, 20, 10, 5, and 2 meters. The peak wind speed and the standard deviation (during the one minute interval) are also recorded. The Wind Speed sensors are calibrated annually in a Met One Wind Tunnel. Prior to December 30, 2009 at 12:35 MST, the wind speed sensors were measured using a Campbell Scientific SDM-INT8 interval timer, which samples the sensors at a high frequency (up to 1 microsecond) and reports the average value to the data logger.
SD-201 Wind Direction o from N 09/23/1996 - see database 0.0792 o/mV (CR23X)
360 o/mV (CR3000)
[DQS]
[Maint]		 The mean wind direction vector at 80, 50, 20, 10, 5, and 2 meters. The wind direction (at the peak wind speed) and the standard deviation (during the one minute interval) are also recorded. Annually a Functional Check Only (FCO) is performed on the wind direction sensors by Met One.
T-200 Temperature oC 09/23/1996 - see database see database (click S/N)
The PRT temperature sensors are at 80, 50, and 2 meters and are mounted in an aspirator. The PRT sensors are calibrated annually at the NREL Metrology Lab and the coefficients were derived from the temperature vs. resistance calibration data. The temperature which is a function of resistance, is calculated using the following third order polynomial: Temp(R) = C0 + M*(C1*R + C2*R2 + C3*R3), where R = Resistance (Ohms).
BP200B Dew Point Temperature oC 09/23/1996 08/22/2018 23352-001 Inst. P16
The dew point sensor is at 2 meters. This is a new sensor that is using the factory calibration, therefore uses Campbell Inst P16 to calculate the cell temperature from resistance. The dew point is then calculated using this formula: Tempdp=0.68434*Tempcell-23.88; if Tempdp<0, then Tempdp*=1.1.
SF52 Dew Point Temperature oC 08/23/2018 - see database 0.02oC/mV - 40oC
The Michell dew point transducer is mounted at 2 meters and has an accuracy of +/- 2oC.
(calc) Relative Humidity % 09/23/1996 - n/a n/a
The relative humidity is calculated in the datalogger using dew point and temperature at 2 meters.
(calc) Specific Humidity g/Kg 08/24/2001 - n/a n/a
The specific humidity is calculated in the datalogger using dew point and station pressure.
(calc) Wind Chill oC 08/24/2001 - n/a n/a
The wind chill is calculated in the datalogger using temperature and wind speed at 2 meters. As of Dec. 13, 2002 the formula is based on the new National Weather Service method described on the NOAA web site. Note: Prior to this date wind speed at 10 meters was used.
(calc) Average Wind Shear oC 08/24/2001 - n/a n/a
The wind shear is calculated in the datalogger by taking the difference in wind speed at two adjacent levels and dividing by their distance (in meters) from each other. This is done for each pair of adjacent levels and then all five are averaged.
AIR AB-2AX Station Pressure mBar 09/23/1996 - 4D0239 0.052 mBar/mV+740mBar
The Pressure Transmitter is physically mounted inside M2 shed, however the measurements are made outside at an elevation of 1857.5 meters. The pressure sensor is calibrated every two years at the NREL Metrology Lab
(calc) Est. Sea-Level Pressure mBar 08/24/2001 - n/a n/a
The approximate sea-level pressure is calculated using station pressure and site elevation.
302-B Precipitation Gauge (tipping bucket) mm 09/23/1996 - - 0.254 mm/count
[DQS]
[Maint]		 The accumulated precipitation is outputted by the datalogger and reset every midnight (standard time). The Belfort heated precipitation gauge is mounted a few feet above ground level near the tower.
4212/12 Aspirator Fan Speed RPM 08/24/2001 - - 30 RPM/Hz
Aspirator Fans are spec'd at 3050 RPM (open air) and run at approx. 2900 RPM when installed in the 2m aspirator (higher level aspirators will be lower). Prior to January 25, 2002 at 12:00 MST, the aspirator status was reported by a microswitch connected to a baffle, if the value is zero then the aspirator may be malfunctioning.
- Logger Battery Voltage V 08/24/2001 - - -
CR23X internal battery voltage. The CR23X data logger is located inside the M2 shed. As of 8/22/2018 at 9:24 MST the logger was upgraded to a CR3000.
- Logger Panel Temperature V 08/24/2001 - - -
CR23X internal temperature sensor is located under wiring panel. The CR23X data logger is located inside the M2 shed. As of 8/22/2018 at 9:24 MST the logger was upgraded to a CR3000.
(calc) Turbulence Intensity - 09/23/1996 - n/a n/a
Calculated for all levels (2, 5, 10, 20, 50 and 80 meters) after datacollection (outside the datalogger) and added to the datastream. Turbulence Intensity is the wind speed standard deviation divided by the average wind speed. As of 28-SEPT-2018 @ 8:06 MST, the values are calculated by the CR3000 data logger.
(calc) Richardson Number - 09/23/1996 - n/a n/a
Calculated for 2-50m, 2-80m, and 50-80m after datacollection (outside the datalogger) and added to the datastream. See NREL technical report at bottom of page.
(calc) Friction Velocity (u*) m/s 09/23/1996 - n/a n/a
Calculated after datacollection (outside the datalogger) and added to the datastream. See NREL technical report at bottom of page.
(calc) Est. Surface Roughness m 09/23/1996 - n/a n/a
Calculated after datacollection (outside the datalogger) and added to the datastream. See NREL technical report at bottom of page.
(calc) u* Quality Control (r2) - 09/23/1996 - n/a n/a
Calculated after datacollection (outside the datalogger) and added to the datastream. See NREL technical report at bottom of page.
(calc) Power Law Coef. (2-80m) - 09/23/1996 - n/a n/a
Calculated after datacollection (outside the datalogger) and added to the datastream. See NREL technical report at bottom of page.
EFM-100 Atmospheric Electric Field kV/m 07/22/2010 02/18/2021 unknown n/a
Measured by a Boltek EFM-100 Atmospheric Electric Field Monitor mounted a few hundred yards east of the M2 tower. Data is collected by an independent system and added to the datastream by MIDC every minute. As of 28-SEPT-2018 @ 8:06 MST, the CR3000 data logger collects data directly from the Boltek computer located at NWTC; the CR3000 samples the EFM every 2-seconds and reports the 1-minute average.
CS110 Atmospheric Electric Field kV/m 05/18/2021 - unknown n/a
[DQS]
[Maint]		 Measured by a Campbell Scientific CS110 Electric Field Meter mounted about 400 yards to the northwest of the M2 data shed. Data is collected by the included CR1000M data logger and merged with the primary CR3000 datastream by MIDC every minute. The CR1000M samples the EFM every 1-second and reports the 1-minute average, minimum, and maximum. The leakage current (average nano-Amps) and the status code (1 minute maximum) is also reported. Status codes are as follows:
  • 1 = Good instrument health; 250 mV measurement range
  • 2 = Good instrument health; 2500 mV measurement range
  • 3 = Good instrument health, but sensor overrange; 2500 mV measurement range
  • 4 = Good instrument health, but had to properly position shutter; 250 mV measurement range
  • 5 = Good instrument health, but had to properly position shutter; 2500 mV measurement range
  • 6 = Good instrument health, but sensor overrange and had to properly position shutter; 2500 mV measurement range
  • 7 = Measurement made, but low external 5V supply
  • 8 = Measurement made, but datalogger skipped scan detected
  • 9 = Measurement made, but input power <9.6V
  • 10 = Measurement made, but datalogger watchdog error detected
  • 11 = Measurement made, but leakage current exceeds compensation range of +/- 4.2 nA
  • 12 = Failed charge amplifier self check (missing value reported for EFM)
  • 13 = Large closed-shutter offset voltage (missing value reported for EFM)
  • 14 = Motor move error; incorrect number of motor steps to close shutter (missing value reported for EFM)
  • 15 = Motor move error; encoder UPCNTs or DNCNTs < 24 (missing value reported for EFM)
  • 16 = Can't properly position shutter (missing value reported for EFM)
- Logger CF Change Count counts 10/11/2018 - - -
A counter that indicates the number of calibration factors (CF) that were changed during a day (value is reset to zero at midnight). Calibration factors for instruments collected by data logger are stored in a text file in memory, the logger will read the file on request (by chaning a flag in memory) and also at midnight, the number of values that change are indicated by the counter. A negative number indicates an error occured (-1 = line read error, -2 = file open error).
CH1 Direct Normal W/m2 06/01/2021 - see database see database (click S/N)
[DQS]
[Maint]		 Direct normal shortwave irradiance as measured by an Kipp & Zonen Model CH1 Pyrheliometer with calibration factor traceable to the World Radiometric Reference (WRR). The instrument is swapped out (with SN 080035 or SN 080034) and calibrated annually by NREL at the Solar Radiation Research Laboratory (SRRL). The CH1 is mounted several feet above ground level on a 2AP Solar Tracker (following the sun).
CMP11 Diffuse Horizontal (Ventilated) W/m2 06/01/2021 - see database see database (click S/N)
[DQS]
[Maint]		 Diffuse shortwave irradiance as measured by an Kipp & Zonen Model CMP11 Pyranometer with calibration factor traceable to the World Radiometric Reference (WRR). The instrument is swapped out (with SN 140911 or SN 091084) and calibrated annually by NREL at the Solar Radiation Research Laboratory (SRRL). The ventilated CMP11 is mounted several feet above ground level on a 2AP Solar Tracker (shaded).
Notes:

[NREL] [MIDC] [Flatirons M2]