3.0 Performing a Gradio Calibration in MAT Job 1. Click the Tool menu, then scroll down and select Acquisition. 2. From the Acquisition sub-menu, select Raw. 3. With the tool sitting in Air write down the frequency on Channel 9. This is your first calibration point. 4. Place the tool into a tube of water. Make sure the water is covering the upper port. 5. After the frequency on Channel 9 stabilizes write down this new value. This will be your second calibration point. 6. You may want to repeat the process to double check your numbers. Note: Remember that after the Gradio has been in water it responds a little bit different than when it was dry. This is normal, however most Gradio calibrations for the same tool should stay pretty close to the same numbers over several jobs.

3.1 Retrieving a Gradio Calibration in MAT Job After the frequency values have been written down the operator must create a calibration file from them. To create this calibration file the operator must enter these files in Premier Logger as described in the following section 3.2. After the Gradio calibration file is created the operator should be able to click on the Gradio row in the Serial No. column in MAT Job to choose the calibration name as shown below.

If the calibration name does not appear as shown above it means one of two things. The calibration file was never created or the calibration file was created after MAT Job was opened. If the calibration file was created after MAT Job was opened save your work and re-open MAT Job with the saved job file. The calibration file should appear in the list. The calibration can be performed at any time before the data is merged with the depth to create the premier logger files (*.pre).

3.2 Saving the Calibration in Premier Logger Premier Logging performs a linear two-point calibration for production logging sondes to calculate a gain and offset that will be used to convert an acquired raw frequency to the required engineered units. To Calibrate a PL Sonde (Gradio): 1. In the Job Settings tree list, click on the sonde name, not the plus sign, that will be

calibrated. The sonde properties will be displayed in the current view of the settings dialog.

2. Click the Calibrate… button to start the 2-Point Calibration wizard.

2-Point Calibration Wizard After each step is complete click Next to go to the next step. STEP 1 of 5 Selecting Sensor to Calibrate

• Select the sensor to calibrate and specify a new serial number for the sensor. If the sonde calibration will overwrite an existing calibration, select the serial number from the available list. Since a Gradio calibration is performed for every job you can overwrite your previous calibration. You may want to keep a backup calibration as a reference, but this is not necessary.

STEP 2 of 5 First Calibration Point

• Enter the standard value that is required from the sensor in the first known well condition. For example, the first Gradiomanometer calibration point would require the tool to be placed in air or a light phase and calibrated to a value or 1.2 kg/m³.

• For Real Time Logging the sensor will be sampled and averaged over a 10 second period. To obtain a good calibration, the sensor reading must be stable. This can be observed by a “small” standard deviation reading.

• For Memory Logging enter the frequency, Channel 9, you obtained in the MAT Job program when the tool was sitting in air.

STEP 3 of 5 Second Calibration Point

• Enter the standard value that is required from the sensor in the second known well condition. For example, the second Gradiomanometer calibration point would require the tool to be placed in water or a heavy phase and calibrated to a value or 1000 kg/m³.

• For Real Time Logging the sampling process will be performed exactly as the first calibration point was.

• For Memory Logging enter the frequency, Channel 9, you obtained in the MAT Job program when tool was sitting in water.

A Sample screen shot of what Step 2 and 3 look like. The only way to tell the difference between those 2 pages is the step number in the title bar.

STEP 4 of 5 Verifying the Calibration

• For Real Time Logging after both calibration points have been taken, the 2-point calibration can be verified to check the validity of the calibration. The verification process will provide a calibrated value for the current frequency. This does not work for Memory Logging.

Note: If the tool hasn’t been moved since the last calibration point was completed, the calibrated value will match the 2 cal point value.

STEP 5 of 5 Confirm Calibration • Trace properties can be modified as needed. • Accept the calibration by clicking the Finish button. Clicking the Cancel button will

cancel the entire calibration process and you will be forced to restart from the beginning.

3.3 Retrieving the Calibration in Premier Logger To retrieve an existing Sonde Sensor calibration:

1. Click the required sonde, Gradio, in the Job Settings tree list to display the sensor properties in the current view.

2. Select the tool calibration serial number from the available list. The Retrieve Calibration button will become enabled when the serial number has chosen.

3. Click the button to retrieve the calibration. The sensor’s gain and shift values will change to reflect the values that were calculated in the calibration.

In Memory Logging it may be necessary to choose a gradio calibration this way, if the operator has already created the premier logger files (*.pre) and you performed a gradio calibration after the fact. This is not very common.