MDG 2024 asks for three density checks. Every morning, before sales and by 10 AM, test a nozzle sample. When a tanker comes, test each compartment against the invoice, within ±3.0 kg/m³. After decanting and dispensing at least 50 litres, test the mixed product in the tank. Record all of them in the density register.
1. The morning density
Clause 1.4.1 (c): the dealer “shall draw product sample from the pump nozzle in the morning and record the morning opening density @ 15°C before commencing daily sales.”
Clause 5.1.9 sets the deadline: the morning density must be checked and recorded by 10 AM every day.
2. Each tanker compartment
Before decanting, drain about 20 litres from the manifold of each compartment into a clear glass container and test it for density and temperature. Each compartment’s density at 15 °C must be within ±3.0 kg/m³ of the invoice density (clause 1.2 iv and viii). Use the density variation calculator.
3. The composite density after decanting
Clause 1.2 (xiv): after decanting, dispense at least 50 litres through the pump, then sample from the nozzle. The density at 15 °C of this mixture is the new reference for the tank until the next morning.
The density register
Annexure 1 of the MDG gives the format, one page per tank per month:
| Date | Morning density | Tank truck receipt density (by compartment) | Density at 15 °C as per invoice | Density at 15 °C after decantation and after dispensing 50 litres |
|---|
Keep the register for the current and the previous financial year. Clause 5.1.12 treats a missing density register as an irregularity.
Make it quick
The Dip Density app keeps every density reading with its date and time and shares a month as a PDF or spreadsheet. It does not replace the register the company asks for, but it makes filling it in a copy job.
Figures here are for reference. Your oil company’s certified calibration chart, approved instruments and the Marketing Discipline Guidelines always prevail.
Questions
What if an inspector comes before I have taken the morning density?
Before 10 AM the inspector uses the previous morning's density, or the previous day's composite density if a load came. After 10 AM the morning density must be there. If the reference density is not available, sales and supplies are suspended and samples are sent for testing.
Why dispense 50 litres before the composite sample?
The pipe from the tank to the nozzle holds fuel from before the load. Dispensing at least 50 litres pushes it out, so the sample is the new mixture in the tank.