Field - Gauge Standardization

Table of Contents

Purpose

A nuclear density gauge must be entered in the system by your MetaField Administrator for it to be available for a Density Test. A new gauge requires 5 standardization counts to be entered.

MetaField requires that a gauge be standardized each day per ASTM requirements. MetaField enforces this by only allowing gauges standardized that day (calendar day, not rolling 24 hour period) to be used for field density tests. The standardization date of a gauge must match the test date of a test in order for the gauge to be available for selection.

Gauges are required to be calibrated / verified by ASTM standard annually, or whenever the gauge is determined to need repair. We recommend that when these events occur, the field technician run the MetaField standardization 5 times using the resulting counts to reset the gauge to the calibrated / verified count. Ongoing daily standardization then uses the calibrated / verified count as the new benchmark.

How to Standardize a Nuclear Gauge

To standardize a nuclear gauge, select the Gauge Standardization button from the MetaField Field menu. The following menu will appear. Select the name of the gauge you wish to standardize and click the Standardize Gauge button.

Method

Depending on the gauge selected, MetaField will automatically adjust according to the Method the gauge was calibrated (Standard Count or Radioactive Decay)

Standard Count

The following will appear after you select a gauge that has been calibrated via Standard Count method.

Supply the Density and Moisture values from your gauge
Click the Perform Test button
Review the standardization results
Save the standardization results if valid or re-enter the standardization data if data was entered in error

Standardization Date will not default to a date. Pay careful attention when entering this date. That date you enter must be >= the last standardization date you entered, so it is important you enter your standardization data in the order they were done. It is recommended that firms make it a practice of entering their standardization data as soon as possible (ideally on the job site after you run the standardization) and no later than the day the gauge was standardized.

The standardization is based on the previous four (4) standardization counts along with the current values for that day.

To determine if the moisture count passes, the absolute value of the following is evaluated:

(New Moisture - Average Moisture) / Average Moisture <= gauge's Rx Moisture Limit / 100

To determine if the density (1 and 2) count passes, the absolute value of the following is evaluated:

(New Density - Average Density) / Average Density) <= gauge's Rx Density Limit / 100

Standard Count (Troxler 3450 Gauges)

The following screen will appear if a gauge is calibrated to record 2 density readings. This is mainly used to support Troxler 3450 gauges.

Supply both Density and Moisture values from your gauge
Click the Perform Test button
Review the standardization results
Save the standardization results if valid or re-enter the standardization data if data was entered in error

If the correct Gauge ID does not appear on the list, contact your MetaField Administrator to have it added.
On the Gauge Standardization screen, you will be prompted to enter 5 sets of Density and Moisture readings the first time you use a Gauge, and 1 set for each daily standardization thereafter.
Depending on the Gauge Category, you will need to enter Density Counts and Moisture Counts or Density Counts only. The Gauge Category is determined by your MetaField Administrator.
Be sure to save your standardization results, otherwise the gauge will not be available when performing a density test that day.

“Accurate” does not mean the result is “True.” It means that the field technician has validated that the counts entered are correct. There are times when the gauge standardization may fail, but the gauge does not need maintenance. You should follow your company’s procedure for dealing with these exception situations.

Radioactive Decay

The following screen will appear after you select a gauge that has been calibrated via Radioactive Decay method.

Supply the Standardization Date
Supply the Density and Moisture Standard Counts Measured from the gauge
Click the Perform Test button
Review the standardization results
Save the standardization results of valid or re-enter if data entered produced a standardization fail.

Tip

If the correct Gauge ID does not appear on the list, contact your MetaField Administrator to have it added.
If the Calibration Date or Calibration Standard Counts appear incorrect, contact your MetaField Administrator.
Both Density and Moisture tests must pass for the gauge to become available for testing.

Post-Save Options

Once your counts are saved, Gauge Standardization is complete. At this point, you will be given 3 options:

Field	Description
Enter Another Count	Select this option when the gauge standardization failed, but there is an exception to be considered (e.g. humidity).
Standardize Another Gauge	Select this option to enter standardization counts for a different gauge.
Perform A Soil Density Test	Select this option to visit the project selection screen and begin the Soil Density Testing process.