Data Loggers (TSAWR & LPR-200)

(originally written by F. Bozinovic March 2024)

Items Required

• Multimeter 
• Power supply  
• Correct solar regulator cable 
• Solar regulator (unmodified) with correct voltage 
• Battery (with enough charged) 
• GPS antenna 
• SD card (FAT32 formatted) 
• Sensor (known working) 
• Correct sensor cable 
• Test Power Plug device 

Power Test

Install a known working (and charged) battery into the recorder and turn ON the main power switch, verify that the recorder powers ON correctly. 

Verify the LCD screen turns on and begins clearly displaying the ANU logo and system parameters correctly once the recorder powers up. Look for signs of flickering, blurring or any other visual artefacts. 

With the recorder powered ON, using a multimeter, test the bias voltage on GPS antenna port; the reading should be 3.3V (outer shell is negative and centre pin is positive). 

Connect “Test Power Plug” into the sensor port and verify the light is turned on, this indicates the power will be correctly delivered to the sensor. 

System Test

• Verify LCD screen works correctly. 
• Check that the keypad is responsive and functions correctly. 
• Verify recorder has GPS fix acquired and information is displayed. 
• Insert SD card and verify the latching mechanism holds the card and releases it. 
• Verify the SD card is detected and can be erased. 

System information

Record the Firmware version. 

In the Menu under “System Information”, verify that the serial number matches what is written on the case.

Functional Test

Charging

Verify the battery is charging (LPR differs from TSAWR, additionally, TSAWRs differ between each other based on firmware version). 

Set-up an external power source, by connecting a solar regulator to a power supply  and set voltage to 18V DC. Verify the regulator is supplying the correct voltage of 7.7V and then plug into the “External Power” port of the recorder.

Navigate to “System Information” in the Menu and note the battery icon will have a lightning symbol indicating it’s charging, also observe the state of charge % is increasing under. 

Sensor Reading

Live Seismometer Data is used ONLY for functional verification. It is an indicator that all connections to the sensor and output response is correct. 

Place the recorder on flat surface bench/ table and connect the sensor (ensure the sensor is not tilted, shaken or rough-handled). Level the sensor using the bubble as guide. Turn ON the recorder wait until the self-check has completed and the recorder has acquired GPS fix. Set the parameters to read the correct sensor. 

To verify the sensor is detected and registering, perform a controlled test is performed by having the person press down on the table with their body weight (similar to performing a slow CPR). The flexing of the table will be detected by the sensor and will be clearly visible on screen. This will verify the sensor-cable and the internal digitizer are working correctly.

Recording test

Insert SD card and erase the content. 

Set-up the System Parameters (sensor type and interval frequency). 

Ensure the recorder has a GPS Fix. 

Select the recording setting in the menu. 

Ensure to allow sensor data recording of overnight or at least 4 hrs. 

Verify the data has recorded correctly by running a power spectral analysis (PSD) script. 

Troubleshooting

Sensors

Sensors can be tested in many ways...

... via Centaur (Nanometrics sensors)

(originally written by F. Bozinovic May 2024)

Introduction

Sensor calibration allows user to input an electrical test signal into a connected sensor to simulate ground motion. The resulting digitized sensor output can then be analysed to assess various attributes of the sensor, such as basic functionality,
frequency response and/or sensitivity stability over time. For a high-quality broadband sensor, these parameters typically remain stable over time, so that if the sensor initially meets manufacturer’s specifications and has not suffered damage,
then calibration is usually not required. However, calibration can be a useful quality control check if it is suspected that the sensor may be defective or damaged after multiple deployments.

Process

The Centaur data recorder can generate and output an analog signal using a 16-bit internal digital-to analog converter (DAC). The DAC output is applied to the sensor for calibration purposes via the matching sensor cable. Make sure to use manufacturer cables as the correct signal lines have been connected to the correct pins of the mating connector. The Centaur CTR, CTR2 and CTR3 series models may generate signals of up to ±5 V amplitude, while the Centaur CTR4 series models have an enhanced calibration output.

Calibration output signal actions are launched from the Waveform page in the Centaur Web interface. A synthetic waveform signal generator allows you to generate sinewave and pseudo-random binary (PRB) signals on demand. User can configure the sine frequency or PRB pulse width, signal duration and amplitude as well as specify lead-in and lead-out silence intervals before and after the calibration waveform. One can also select and play a calibration file containing any other desired digital time series waveform that by uploading it to the Centaur, such as a swept sinewave, step function, random noise, or chained PRB sequence.

The following sample calibration files are supplied with the Centaur. These files may be used to visually verify functionality and approximate sensitivity of the sensor by inspection of the output waveform: 

• sine_5V_30s generates a 1 Hz sine wave with 5 V amplitude lasting 30 seconds. 
• step_0V_to_5V_15s generates a 0 V signal for 15 seconds followed by a positive 5 V step function lasting 15 seconds. 
• prb 1V 20ms 10min generates a 10 minute PRB sequence using 20 ms pulses and 1 V amplitude.
• prb 1V 5s 150min generates a 2.5 hour PRB sequence using 5 second pulses and 1 V amplitude.
• prb 2V 5s 8hr generates an 8 hour PRB sequence using 5 s pulses and 2 V amplitude.

Procedure

1. Log-in to the Centaur Web Interface and use the Admin credentials 
2. Navigate to the Health page and verify that the sensor is properly levelled and recognised by its serial number. 
3. To configure the calibration parameters, navigate to the Waveform page. 
4. From the Calibration panel at the top page, select Type from the drop-down list and  choose Sine. 
5. For the CTR4 series models, additional option to select between Voltage or Current is available. 
6. Click on the Configure button to access the calibration dialog box for the selected Playback. 
7. Configure the signal characteristics by selecting 5V, 30 sec with gain of 1. 
8. Configure the padding before and after the calibration signal, enter 5 seconds. 
9. The Duration (s) time can be made shorter or longer as required by user. NOTE, for shorter frequencies a longer duration will be required for the signal to complete its full cycle and to capture the entire waveform on the screen. 
10. Click OK button to close the dialog box and save the settings. 
11. Click the start calibration button   to begin the process. Approximately 5 seconds of time padding ( as set in Step 8) will past before the sensor responds to the injected signal and display the sine wave feedback response. 
12. The calibration will end after 30 seconds (as set in Step 7) or can be terminated manually by pressing the stop button. The calibration will then stop after 5 seconds and any configured lead out silence will be skipped. 
13. Click on the pause button on the bottom of the page to stop the live stream and use the arrows to centre the sine signal response. Note that the screen waveform will turn Blue and the stream will freeze. Avoid capturing live streaming signal! 
14. Once the response signal is cantered, perform a screen-capture “Print Screen” button or use “Snippet” tool and save the captured image locally. In the nametag, include a Serial number, date and sensor type. 
15. Archive and back-up the file. 

... via data comparision (vs S1.AUANU)

CODE & Guide to use code

Solar Panels

(originally written by F. Bozinovic November 2024)

Testing solar panels is vital for any remote seismic station, since the solar panel ensures that the batteries are kept charged throughout the day. Therefore, reliably testing them ensures only the working panels are installed on remote sites, ensuring success of the site operation and serviceability.

This procedure describes the method for testing solar panels and determining how to identify defective panels. The testing of solar panels should be performed outdoors, under bring sun to obtain accurate results.

Following materials are required

• Solar panel for testing 
• Digital multi-meter (DMM) 
• Load Resistor (designated power resistor of known value) 
• Wire leads 
• Alligator clips 
• Spreadsheet with formulae 
• Marker/ pen 

Test Method

1. Clearly label each solar panel to keep track of measurements. 
2. Record the manufacturers power rating of the solar panel. Perform all measurement outdoors under bright sunny conditions! 
3. Using wire leads and/ or alligator clips measure the open circuit Voltage and Current of the solar panel and record. Make sure to change the dial on the DMM as taking measurement under incorrect setting will damage the DMM! 
4. Using wire leads and/ or alligator clips connect the Load Resistor and measure the Voltage across the resistor and record. 

Ensure the load resistor value is accurately measured and recorded. A difference in 0.1 Ohms results in 1% power difference in calculated result.

Once all the solar panels have been tested and their results recorded, enter their values under the corresponding panel label in a spreadsheet. The cells containing preset formula will auto-populate and provide the results.

If the spreadsheets need to be developed, follow the steps in the next section. 

Developing a spreadsheet

Create a spreadsheet with following cells 

For cells in rows (Solar panel #ID), (Voc), (Ioc), (Vrl), enter the recorded values. 

(Rload) cell is the Load Resistor value. This cell is a constant and does not need to be copied for all entries. 

Inside the “Vrl (Theoretical)” cell enter the following formula using the corresponding cells. 

V_{RL}=I_{oc}\times R_L

Inside the “Rated Power” cell enter the following formula using the corresponding cells. 

P_{oc}=V_{oc}\times I_{oc}

Inside the “Load Power” cell enter the following formula using the corresponding cells. 

P_{RL}=\frac{V_{RL}}{R_L}\times V_{oc}

Inside the “Power Loss %” cell enter the following formula using the corresponding cells. 

The calculated values that are negative represent power loss, and positive values are power gain. Performing “conditional formatting” on these cells with colour gradient (defined by colour break limits) would yield visually easy to recognise defective panels.

Power\ Loss\ \%=\frac{P_{RL}}{P_{oc}}\times 100-100

Perform all the calculations for each solar panel ID entered. 

Solar panels with power loss of 20% or more should be clearly marked as defective and not be used in any future deployments.