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#189 vibration problem in #40 anemometer

Posted by techfe on 21 May 2009 - 04:55 PM

We have had vibration problems in #40 anemometers (serials 37538,37534,37535 and other 3 of them) all bought in 2007 and 2008. How warranty works?


Could you please tell me what to do?


 


 


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#186 White Paper: "Investigation of the NRG #40 Anemometer Slowdown" by S...

Posted by Julia Austin on 14 May 2009 - 01:31 PM

AWEA Windpower 2009 Paper V5-11-09.pdf

Paper submitted for AWEA Windpower 2009 Conference, 4 - 7 May 2009, Chicago, IL, USA

"Investigation of the NRG #40 Anemometer Slowdown"

by Steven H. Clark, Principal Investigator

 Owen Clay, John A. Goglia, Timothy R. Hoopes, Lawrence T. Jacobs, R. Paul Smith


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#104 Could you elaborate on recommendations for how to use data from masts with co...

Posted by Julia Austin on 18 December 2008 - 10:00 AM

Q: Could you elaborate on recommendations for how to use data from masts with corrupted sensors?



A: It is best to compare the ten-minute average of two sensors that are mounted at the same height. By looking at the difference (or ratio) between these two sensors, it can be determined whether one or both are experiencing excessive drag. (See slides 8 and 10 in the presentation for a visual depiction.) Typical data quality checks can then be used to filter the data. If unsure, it is best to consult an expert in data analysis.


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#103 Can we get a transcript and copy of this presentation?

Posted by Julia Austin on 18 December 2008 - 09:58 AM

Q: Can we get a transcript and copy of this presentation?



A: Both are available on our tech forum, http://forum.nrgsystems.com/forums


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#99 Do you have an estimated timeline for when field testing and reengineering [s...

Posted by Julia Austin on 18 December 2008 - 09:56 AM

Q: Do you have an estimated timeline for when field testing and reengineering [sic] will be complete?



A: We can?t provide specific timelines. Our validation criteria require that we collect data from 50 pairs of anemometers for eight weeks. Only when we have sufficient data, and consensus that the sensors are performing up to pre-2006 standards, will we form conclusions and move ahead. There is a short amount of time on either side of those eight weeks to complete engineering activities, deploy sensors, and ramp up manufacturing.


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#96 Is one of the spikes on the frequency plot [from the webinar presentation] th...

Posted by Julia Austin on 18 December 2008 - 09:53 AM

Q: Is one of the spikes on the frequency plot the actual rotation rate?



A: These smaller spikes in the frequency plots are typical natural frequencies of the boom.


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#93 How do we determine if the data we have collected is valid?

Posted by Julia Austin on 18 December 2008 - 09:21 AM

Q: How do we determine if the data we have collected is valid?



A: Comparing two sensors mounted at the same level by taking the difference (or ratio) of the ten-minute average readings is the simplest method. The two sensor readings should track fairly well, but if one sensor is in this vibratory mode, then the difference (or ratio) between the two will diverge. Keep in mind that two sensors at the same level may not track exactly the same due to other factors (e.g. wind regime, mounting configuration, site terrain, etc). The level of scatter should be excessive. If unsure, it is always best to consult a data analysis expert.


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#91 Once an anemometer shows signs of dragging, how often will it go into the vib...

Posted by Julia Austin on 18 December 2008 - 09:11 AM

Q: Once an anemometer shows signs of dragging, how often will it go into the vibratory mode? 30% of the time in 5-10m/s wind? 70%?


A: An anemometer susceptible to the vibratory mode will tend to switch into its normal mode at higher wind speeds (above 10 m/s) and at very low wind speeds (below 5 m/s). In the 5-10 m/s range it will vary by sensor and its environment. In answer to this specific question, we don't have a basis by which to identify a typical percentage. We estimate that 20-30% of all sensors manufactured after 2006 are affected by this issue.


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#729 NRG 200 Checking Calibration

Posted by steve melling on 15 August 2013 - 12:16 PM



Hi,



I've had an
NRG 200 Wind Vane for two years. There are some
discrepancies in correlated wind direction
data and i would like to check the calibration of the instrument on
decommissioning of the met mast. I see there is some information in the
documents section of the site, however, if the calibration is out, can i tell
by how much and then modify my recorded data accordingly?



Any responses or advice greatly
appreciated,



Thanks, 

Steve


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#235 NRG #40 anemometers

Posted by Steve_Heidra on 03 August 2009 - 12:11 PM

 I have just tested two uncalibrated #40 anemometers and a calibrated #40 anemometer in a wind tunnel under identical conditions.  I was really concerned about the results and tried to make contact with NRG with no response as yet.  I tested between 1 and 20 m/s.  Above 5 m/s the results showed reasonable agreement.  Below 5 m/s the new calibrated #40 show significant sticking.  Extrapolating the above 5m/s calibrated results below 5 m/s indicates the uncalibrated #40 anemometers (used for 8 months) showed no noticeable sticking down to 1 m/s, but rather overspeeded by more than 1 m/s.  When used in an MCP analysis for a low wind speed site these results are of a high concern.  COME ON NRG.  We need some answers.  I feel I might as well buy some cheaper product or go for a product which you can trust. 


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#1704 Download partial files (yes or no)

Posted by ibrochim on 27 May 2016 - 11:57 AM

Dear all,

 

I have a problem with iPack setting, in tab "settings" there's a choice for "Download partial files". When i choose (thicked) "yes" and i press "call now" email succeed sent but when i change with "no" and i press "call now", error 2421 appears and disconnecting suddenly.

what should i do?. Thank you

 

regards


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#164 what is vibratory mode?

Posted by ROHAN JADHAV on 22 April 2009 - 03:31 PM

 What do you mean exactly when saying anemometer is in vibratory mode?

 Regards


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#157 Link to slides from last webinar presentation

Posted by ColinMurray on 15 April 2009 - 11:23 PM

Is there a link to the slides from the last webinar presentation?

Regards,

Colin Murray


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#118 Update on #40C Sensor Shipments

Posted by ltj on 20 January 2009 - 01:00 PM


For some time now we have been studying and checking NRG #40 anemometer tolerances and manufacturing processes in tremendous detail to understand what has been causing some of the sensors to intermittently underreport wind speed. 

 Recently we reported that a vibratory mode had been identified as the cause of the slow down. As a result of our analysis and testing, we have revised the specifications of certain materials and tightened the tolerances of certain dimensions of the sensor.  These improvements have eliminated the vibratory mode in test sensors in our laboratory. We have further validated these improvements in wind tunnel tests and in limited field tests. Final validation of these improvements must await the results of longer term field data which will take another 6 to eight weeks.

We are confident, based upon the results of our laboratory testing, that these changes have a high potential to significantly reduce the probability that a sensor will degrade in the field. Therefore, we believe that it is appropriate to integrate these modifications into the NRG#40 immediately.  As of January 5, 2009, all sensors will ship with the improvements.


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#116 Icefree3 sensors

Posted by GemmaAllen on 16 January 2009 - 07:06 AM

Is it possible that your Icefree3 anemometer is affected by the vibratory mode issue?


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#108 Does NRG plan to develop any tools that will aid in identifying and cleaning...

Posted by Julia Austin on 18 December 2008 - 10:03 AM

Q: Does NRG plan to develop any tools that will aid in identifying and cleaning these areas of bad data?



A: We are working closely with our round table experts and hope to share some of our findings on techniques and methodologies to address this issue.


 


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#100 What is your recommendation on parallel installs other manufacturers' sensors...

Posted by Julia Austin on 18 December 2008 - 09:56 AM

Q: What is your recommendation on parallel installs other manufacturers' sensors alongside the 40C to compare the data (i.e. at what height and direction to install new, third party sensors)?



A: There is no consensus on best practice as it relates to tower configuration; preferences will vary depending on priorities. Some of our customers pair different anemometers with #40Cs at the same level. The height and direction is typically dictated by site conditions and prevailing winds. 


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#90 If I buy sensors now, could they have this vibratory mode?

Posted by Julia Austin on 18 December 2008 - 09:10 AM

Q: If I buy sensors now, could they have this vibratory mode?



A: Yes, until you hear otherwise. We estimate that 20-30% of all sensors manufactured after 2006 are affected by this issue.


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#671 Using GS sensors without a GS Logger

Posted by Julia Austin on 31 December 2012 - 12:16 PM

Because all GS sensors are "smart" sensors and have their own microprocessor and memory storage, it is possible to install them on site as stand-alone measurement devices without installing a GS-Logger at the base of the tower.   

  

There are a couple different ways to deploy GS sensors as stand-alone measurement devices.  The first is to install the sensors and booms on the tower, connect the sensors to the GS-Pod(s) without using a GS-Logger at all.  At the end of the measurement period, the GS-POD or GS sensor can be removed from the tower and connected to the GS-PAD to download the data.  Any non-GS sensors connected using a GS-ASIM will rely on the GS-ASIM for data storage, so in this case it is the GS-ASIM that is connected to the GS-PAD to download the data.   

  

The major drawbacks to using the GS sensors without a GS-Logger are:

 

1)  loss of real-time boom adjustment utilizing orientation and verticality features (detected by the logger communicating with the sensor and GS-Pod);

 

2)  a lag of up to 24 hours of data that can be pulled from the GS-Pod or GS sensor.  Without the logger at the base of the tower to force the sensors and PODs to "sync", the data set extracted using the GS-PAD may end a few hours earlier than when the GS sensors and GS-PODs were actually removed from the tower.  

  

A different approach that overcomes these drawbacks is to bring the GS-Logger to the site at the beginning and end of the measurement period.  During installation, perform the tower sync function.  Then when you are ready to extract the data, bring the logger back out to the site, do another tower sync, and then the data can be removed from the logger [rather than having to tip the tower down and remove the GS sensor(s) and GS-POD(s) to get the data].


 


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#615 Satellite error

Posted by Aislan on 20 June 2012 - 03:28 PM

Hi


I'm trying to configure a new satellite iPack, but I got some errors:


2140 - Pop3_TIMEOUT_ERR


25110 - GPS_SET_EVT


2150 - POP3_NOMAME_ERR


25108 - CALL SUCESS_EVT


25109 - CALL_FAILED_EVT


2105 - PPP_ERR


These errors occured in different moments when thying to performe a "Call Now". I followed an old configuration that I have from another satellite system that is in use in another mast.


I'm trying to activate two satellite iPacks:


Customer Modem Reference: EAN8447 - Joca Tavares - Rio Grande do Sul


IMSI: 901032240084028


IMEI: 300025010222590


SIM: 8988169224000840281


MSISDN/C: 881692497348



and


Customer Modem Reference: EAN7539 - Asperezas - Rio Grande do Sul


IMSI: 901032240084031


IMEI: 300025010225590


SIM: 8988169224000840315


MSISDN/C: 881692497349

 

Can you help me?


Thanks,


Aislan Theisen.


 


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