Forecourt - Automatic tank gauging

Automatic Tank Gauging (ATG) provides you with real time and accurate measuring of fuel through your dispensers. This is done by comparing dispenser sales to changes within the levels in the tanks. This functionality enables you to easily detect possible theft or leakage.

This system has been designed to support any probe interface, requiring only the product height and optionally water level and temperature.

The following ATG systems have been installed with PCC systems to date.

• Veeder-Root TLS-200 / 250
• Veeder-Root TLS-50 / 300 / 350 / 350R / IB
• Veeder-Root - Magnetostrictive
• Franklin Fueling (Incon)
• OPW
• Gilbarco (VR OEM)
• Red Jacket ATG / ST models
• Red Jacket - Ultrasonic
• Tatsuno Micon Level Gauge
• Tatsuno - Capacitance
• US Test Ultra-sonic
• Enraf / Delft Stic 867 protocol
• Enraf - Capacitance

AUTOCAL - AUTOMATIC TANK CALIBRATION

Background Information

The Postec Forecourt Controller has interfaced to a range of third party ATG systems since 1989. Over this period it was found that the results of the level to volume conversion procedures used by some of the ATG Consoles were not accurate enough for tight wet stock control - though in most cases the readings were much better than manual dips.

During this time Postec also found that many tank gauging systems had very onerous Tank Calibration procedures and automatic tank calibration was only available on the higher priced ATG Consoles.


AUTOCAL – Auto calibration

QuickFuel support the Postec developed ATG software that provides a full wet stock control system with tight level to volume conversion and automatic tank calibration.

This software residents in the Postec Forecourt Controller or PCC and it can be used with any ATG probes and intrinsic safety consoles/barrier boxes that the PCC is interfaced to. This means that when lower specified ATG systems are interfaced to the PCC, they perform higher specified tasks at a lower cost than the higher specified ATG consoles e.g.

• Automatic Calibration &
• Delivery Measurement whilst dispenser sales are in progress

Automatic Calibration –

Postec's AUTOCAL checks a number of conditions before AUTOMATICALLY placing a tank into calibration mode. As the level falls AUTOCAL creates a 500 point strapping chart by analysing real time sales direct from the dispensers (see Figure 1). This provides an extremely accurate height to volume conversion table which forms the basis of the subsequent wetstock reconciliation and reporting system.

If fuel is added during the automatic calibration process, AUTOCAL will suspend and re-activate itself. AUTOCAL will then automatically cease calibration once a predetermined lower level in the tank has been reached.

Delivery Measurement -

Because the PCC monitors the tank levels and dispenser sales in real time, it can accurately measure tank deliveries whilst dispenser sales are in progress. These measurements can be used for delivery confirmation and are vital to the historical reconciliation system.

Leak and Theft Detection

Though sudden loss of fuel over a short period of time will probably be picked up by the most wet stock control systems, leaks and thefts usually take place in smaller amounts over a longer period of time. This type of leak or theft is the most frequent one, harder to detect in the short term but will show up in a comprehensive Historical Wet Stock Reconciliation Report. AlertManager will also send this information in real time to your mobile phone via SMS or email.

Historical Wet Stock Reconciliation

Postec’s Historical Wetstock Reconciliation Report is the culmination of the data collected from the tank probes, dispenser sales and delivery measurements into a single report (see Figure 2). The PCC compiles reconciliation data at 24 hour intervals and stores up to 31 days historic data. This historic reconciliation data can be uploaded from the PCC by 4COM (Postec’s communication software) and appended to a data base to provide historic reconciliation spanning any historical period. This data is also available for use on site if required.

The analysis of this accurately recorded data, together with the hourly tank variance files forms the basis of the leak and theft detection process.

Other Reports

Other reports available from the system include:

• Tank Inventory
• Tank Delivery
• Tank Variance
• Tank Leak Site
• Transaction
• Site Events
• Accumulated Grade Totals
• Dispenser Totals Reconciliation
• Accumulated Dispenser Totals
• Statistics & Summary
• Site Configuration
• Autodial Directory

Samples of the main reports are illustrated in the 4COM section.

Monitoring Action

Besides acquiring data the PCC/ATG System continuously monitors all dispensers, tanks and any other electronic devices in the network. If this monitoring reveals a situation requiring urgent investigation or action e.g. sudden loss, pumps off-line, possible leakage, etc, the PCC can automatically dial out via its internal modem to the appropriate authority as defined by the user. The automatic dial out feature enables clients to customise their monitoring system including:

A) The type of errors that they want reported
B) A level of priority against each error type
C) A table of telephone numbers for organisations/personnel they want contacted automatically depending on conditions of A and B above