With the SpanBox5, there are three methods for drift: drift to phx calibration, drift to cylinder calibration, and VVA drift.
| Drift to phx Calibration |
This type compares the phx calibration value for a given concentration. Pass/Fail is determined on the percent amount in the settings of the Drift positive or negative values.
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| Drift to Cylinder Calibration |
This type follows above Pass/Fail based on the known cylinder concentrations as the benchmark.
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| VVA Drift |
This type uses cylinder concentrations and runs through three test samples for each one. Pass/Fail is based on the average for the three samples.
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Make sure the phx42 is ignited and warmed up before attaching it to the SpanBox5.
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Tap the Drift box on the Home screen.
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Follow the on-screen prompt to confirm the phx42 is attached to THE SAME PORT it was calibrated on earlier in the day.
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Analyzers with a Daily Calibration from today will appear.
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On the right of each analyzer, the latest EOD and Noon drift results will be shown.
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Check the boxes next to the analyzers to be drifted:
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If the analyzer can’t be discovered, it will be grayed out.
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If the analyzer is in range, wait a minute for the SpanBox5 to discover and connect.
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Tap either Noon or End of Day radio button at the bottom of the screen.
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Tap Next.
- Note: If a drift of the same type (Noon or EOD) has already been performed on a unit, it will prompt you to confirm you want the previous drift overwritten.
- Note: If a drift of the same type (Noon or EOD) has already been performed on a unit, it will prompt you to confirm you want the previous drift overwritten.
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If the cylinder information is correct, tap Next. This will auto-advance after 10 seconds. Otherwise, tap Manage Cylinders (you must use the same cylinders used for calibration).
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The Drift process will begin.
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Units will be drifted to the selected cylinders.
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If you are running a standard drift, each gas will be applied once.
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If you are running a VVa drift, each gas will be applied 3 times.
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If a unit fails a gas, it will continue testing the unit while continuing the drift process for the other units.
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Select your name from the Technician dropdown and sign, then tap OK.
| Standard Drift Formula | D = Drift reading C = Calibration reading or cylinder concentration Drift Pct = ((D – C)/C) x 100 |
| VVa Drift Formula | Drift % = ((D – C) / C ) x 100 for each attempt of the drift and then for the overall Drift Pct for the gas Drift Pct = (((D1+D2+D3) / 3) – C ) / C ) x 100 |
| Drift to… | Calibration PPM: Calculates the passing drift PPM using the confirmation PPM value from the analyzer’s Daily Calibration. Cylinder Concentration: Calculates the passing drift PPM using the cylinder’s Actual Concentration value. Both: Calculates the passing drift PPM using first the Calibration PPM and then separately the Cylinder Concentration and requires the drift PPM to pass both. |