Petrol Pump Terms Explained: MS, HSD, Totalizer, DSR, Dip, Density and More

The words used on an Indian petrol pump forecourt and in its accounts, in plain language. If you are new to running a pump, or you are setting up software and the labels confuse you, this page is the place to look things up. Terms link to the guide that explains them fully.

Fuel and equipment

• MS (Motor Spirit). Petrol. Premium grades are sold under brand names but are still MS on the invoice.
• HSD (High Speed Diesel). Diesel for vehicles. LDO (light diesel oil) is a different, rarer product.
• DU (Dispensing Unit) / dispenser. The machine that pumps fuel. Identified by a number (for example 398) or a position (DU-1, DU-2).
• Nozzle. The handle that goes into the vehicle. Each nozzle has its own meter. A dispenser with one MS and one HSD nozzle has two nozzles; a four-nozzle dispenser serves two vehicles at once.
• Totalizer. The cumulative litre counter per nozzle. Only goes up. See totalizer reading.
• Preset. Setting the dispenser to stop at a fixed amount or litres, for example Rs.500 or 10 L.
• Underground tank / UGT. The buried tank holding each product. Each has a calibration chart.
• Dip rod / dip stick. The graduated rod used to measure fuel height in a tank. See dip reading.
• ATG (Automatic Tank Gauge). An electronic probe in the tank that reports level without a dip rod. Found on automated outlets.
• Decantation. Unloading the tanker into the underground tank. See tanker refill record.

Readings and tests

• Opening reading. The totalizer reading at the start of a shift; equal to the previous shift's closing reading.
• Closing reading. The totalizer reading at the end of a shift, taken at the handover minute.
• Fuel Sold. Closing − Opening − Test litres, per nozzle. See shift sales calculation.
• Test litres / 5-litre test. Fuel drawn into a certified measure to check the nozzle's accuracy, then returned to the tank. Subtracted from Fuel Sold. See the 5-litre test.
• ±25 ml. The usual permissible error for a 5-litre draw (0.5%). A nozzle outside it needs calibration.
• Calibration. Adjusting and sealing a dispenser so it delivers the right quantity, done by the dispenser company and verified by Legal Metrology.
• Rate / RSP (Retail Selling Price). The per-litre price in force, revised by the oil companies at 6:00 AM when it changes. See rate change during a shift.
• Density. Mass per volume of the fuel, in kg/m³ at 15°C, checked with a hydrometer. Used to confirm product quality against the invoice.

Shifts and money

• Shift. The period one set of operators is responsible for, between two handovers. Often 24 hours (10 AM to 10 AM) on small pumps, or 8 to 12 hours.
• Handover. The moment readings are taken and cash is counted, closing one shift and opening the next. See handover checklist.
• Operator / DSM (Driveway Salesman) / attendant. The staff member running a dispenser during a shift.
• Expected Amount. Fuel Sold × rate, split at a rate change. What the nozzle should have brought in.
• Cash. Notes and coins handed over by the operator for a nozzle.
• Online. UPI, card and wallet payments recorded against a nozzle. See UPI hisab.
• Pending Due. A credit sale (udhar, khata) to a known customer, recorded against the nozzle and the customer. See credit customers.
• Collected / Submitted Amount. Cash + Online + Pending Dues for a nozzle.
• Difference. Expected Amount − Collected. Zero (or a few paise) means Settled; positive means Short; negative means Extra. See cash shortage.
• Settled / Not Settled. A shift or dispenser whose difference is within a rupee, or not.
• Other sales. Non-fuel sales such as engine oil, recorded by shift but outside the fuel hisab.
• Expenses. Money leaving the drawer for salaries, electricity, tea, repairs. Kept out of the difference. See expenses.
• Refill. A tanker delivery into a tank: date, fuel, tank, litres, amount.

Reports and stock

• DSR (Daily Sales Report). The one-page shift or day record. See DSR format.
• Shift register. The paper book (or app) in which each shift's readings, cash and difference are written.
• Khata / udhar book. The credit ledger, one page per customer: sales, payments, balance.
• Book stock. Opening dip + receipts − meter sales, the stock a tank should hold.
• Stock variation. Closing dip − book stock. Small and two-way is normal; one-way and growing is not.
• Dip chart / calibration chart. The table that converts a tank's mm reading into litres. Unique to each tank.

Rules and bodies

• OMC (Oil Marketing Company). The company whose fuel you sell and whose brand the pump carries (IndianOil, BPCL, HPCL and others). Issues invoices, sets rates, inspects the outlet.
• Dealer. The owner of the retail outlet, licensed by the OMC. RO (retail outlet) is the OMC's word for a pump.
• Legal Metrology. The state department that checks weights and measures, including dispenser accuracy and the 5-litre measure. Keeps the ±25 ml rule.
• PESO. The Petroleum and Explosives Safety Organisation, which licenses the storage of petroleum at the outlet.
• Dealer commission. The dealer's margin per litre, set by the OMC, built into the RSP.