U501-A Specifications:
| Sensor type: | Optical encoder with quadrature output |
| Part number: | U501-A |
| Purpose: | Convert meter shaft rotations to electrical pulses for dispenser controller |
| Pulses per revolution: | 60 ppr (per meter shaft revolution) |
| Channels: | Dual quadrature (A+B with 90° phase shift) |
| Power supply: | 5 V DC, 10-30 mA |
| Output type: | NPN open-collector, square wave |
| Duty cycle: | 50% ±10% |
| Min frequency: | 1000 Hz |
| Max RPM: | 3000 rpm |
| Compatibility: | U101-A, Bennett SB-100 and other 60-ppr-compatible meters |
| Anti-fraud protection: | Yes — quadrature output provides rotation direction sensing |
| Explosion protection: | Ex d IIA T3 |
| Operating temperature: | −40…+70 °C |
| Mounting: | Three M4 screws on meter housing |
| Warranty: | 12 months |
Optical Encoder U501-A — Pulse Sensor for Fuel Dispenser Counter
U501-A — modern optical encoder (pulse sensor) with quadrature output for fuel counter U101-A (Bennett SB-100 compatible) in fuel dispensers. Converts mechanical crankshaft rotations of the counter into electrical pulses: 60 pulses per single rotation = 0.5 liters of fuel passed. Signals are transmitted to the electronic control unit of the fuel dispenser for displaying liters and cost on the display, fraud control, and generation of fiscal reports.
Operating Principle
A code disk with 60 slots around the circumference is fixed on the counter shaft. Between the disk two infrared light-emitting diodes and receivers (photodiodes) rotate. When the disk rotates, it sequentially blocks optical beams — rectangular pulses with 50% ±10% duty cycle are formed at the outputs. Two channels (A and B) with 90° phase shift make it possible to determine not only the quantity, but also direction of rotation — this is used to detect fraud attempts (reverse "rewinding" of the counter).
Why Quadrature Output is Critically Important
- Anti-fraud protection — backward rotation of the crankshaft is detected by the system as a suspicious cycle
- High accuracy of accounting — signal duplication through 2 channels eliminates pulse loss
- Compatibility with modern fuel dispenser controllers — quadrature output is an industry standard
- Stable operation under vibrations — optical principle is not affected by electromagnetic interference (unlike magneto-inductive sensors)
Technical Specifications
- Power supply: 5 V DC, consumption 10-30 mA (max. 90 mA)
- Output: NPN open-collector, rectangular pulse
- Number of pulses: 60 ppr (per rotation of counter crankshaft)
- Channels: 2 (A+B) with 90° ±25% phase shift
- Minimum frequency: 1000 Hz, max. rotations 3000 rpm
- Explosion-proof marking: Ex d IIA T3
Compatibility
U501-A is designed for Bennett SB-100 counters and their clones (U101-A/B). Mounted with three M4 screws directly on the counter body on top. Cable with leads connects directly to the fuel dispenser controller (soldered without connector). Do not confuse with the original Bennett encoder at 256 ppr — it does not fit U101-A due to a different gear ratio.
When Replacement is Needed
- Fuel dispenser shows "0 liters" with operating pump (encoder does not produce pulses)
- Chaotic/unstable counter readings — wiring or electronics damage
- Fiscal module errors when transmitting reports (incorrect quadrature signal)
- Replacement during major overhaul of counter or fuel dispenser
- Cable damage — breakage or chafing
Delivery and Warranty
U501-A in stock. Shipment on the day of payment by Nova Poshta, SAT or shared cargo throughout Ukraine (1-3 days). Manufacturer warranty 12 months. When purchasing a batch for a gas station network or equipping new fuel dispensers — individual terms available. Technical consultations on selection and compatibility from an engineer within 1 business day. Export to Kazakhstan, Moldova, Georgia through NOVA GLOBAL.
Frequently Asked Questions
Is U501-A compatible with Gerkon dispensers?
What is the delivery time?
What is the warranty?
SHIPPING INFORMATION FOR UKRAINE
Our company is committed to fast shipping and delivery throughout Ukraine. We work with carriers that offer the best balance of price and quality, including:
NOVA POSHTA
1-3 days. Delivery speed depends on your location. After placing your order and payment, we ship the same day or the next.
SAT
Delivery time 3-5 days. Speed depends on the distance between sender and recipient. This is the most economical option compared to Nova Poshta.
DELIVERY
Shipping takes 4-7 days. This is the slowest method, but its advantage is the low cost.
FREIGHT POOLING
Shipping is done via shared transport through a dispatcher. Finding a vehicle takes 1-2 days; speed depends on the destination (major cities are faster, remote villages slower). This method is cheaper than the carriers listed above.
We work throughout Ukraine, and on request can arrange delivery via another courier service not on our list.
After placing your order in our online store, please provide the following information for delivery to your region:
- Recipient's full name
- City or town
- Number of the nearest warehouse (if shipping via courier services)
- Mobile phone number
Once the goods are shipped, we will provide you with the waybill number. When picking up your order, please bring your passport and the waybill number.
NOTES:
- The seller is not responsible for the operation of postal / courier services.
- Shipments are insured for full value; in case of damage the carrier is obligated to compensate you in full.
- Shipping costs are paid by the buyer (or by mutual agreement).
- If the requested product cannot be supplied, an equivalent replacement will be offered upon your approval.
If you couldn't find an answer to your question in this section, please contact us for more detailed information.
PAYMENT METHODS
After placing an order for a selected product in our store, we verify stock availability and confirm with you. Payment can then be made using one of the following methods:
- Bank transfer to the company account (VAT included).
- Cash on delivery (payment upon receipt).
Before paying via bank transfer, please contact us to confirm product availability.
Cash on delivery is processed at the carrier's warehouse. The service fee is 2% of the total + 15 UAH for payment processing. For an order of 1000 UAH you will pay 35 UAH for this service plus the shipping cost.
The second method is more reliable as you can inspect the goods on the spot, but it is also more expensive, so before paying you may want to consider which method suits you best.
If payment is received by 12:00, we ship the same day; if payment arrives later, shipping is processed the next day.
For any questions about payment, please contact us — if you haven't found an answer to your question, we will provide more detailed information.
WARRANTY & SERVICE
- Warranty on Gerkon fuel dispensers — 18 months;
- Warranty on Gerkon measuring tanks — 18 months;
- Warranty on level meters — 36 months;
- Warranty on fuel dispenser connection installation — 18 months;
The manufacturer guarantees free replacement or repair of dispenser parts and assemblies that fail due to manufacturing defects, provided that transportation, storage, and operation rules are observed.
