Electronic Registers and Ancillary Equipment Incorporated in Metering Assemblies Specifications (SI/90-156)

8. Except as provided in section 9, any means of adjustment that is used for processing pulses in order to vary measurement results shall be sealable and located so as to be inaccessible without the removal of a portion of the exterior housing of the register.

9. Any means of adjustment that is accessible without the removal of a portion of the exterior housing of the register shall

• (a) have an adjustment range of not more than ±2 per cent of the volume of liquid to be delivered;

• (b) be sealable; and

• (c) not be adjustable while the register is operating.

10. A register may incorporate a means of adjustment that automatically selects a predetermined correction factor that corresponds to the rate of flow, in order to linearize the meter accuracy/flow rate performance curve, where

• (a) no factor can be adjusted to deviate from the adjacent factor by more than 0.25 per cent; and

• (b) the register is designed so that programmed correction factors are readily verifiable either by means of the display or printing of the programmed correction factors or by any other means, such as switch settings or jumper locations accompanied by suitable codes or legends.

• 11. (1) A pulse processing system of a register that is intended for use in a metering installation in which a reverse flow of liquid through the meter can occur shall, in the case of such a reverse flow of liquid, subtract from all registrations the quantity corresponding to the volume of the reverse flow of liquid.

• (2) Where the pulse processing system of a register does not comply with subsection (1), the system shall not be approved pursuant to section 3 of the Act unless the use of the system is restricted to metering installations in which a reverse flow of liquid cannot occur.

• 12. (1) A register, other than a non-resettable register, that incorporates an electronic display shall

  • (a) automatically supply electrical power to all display segments for at least 0.5 seconds and cut the power for at least 0.5 seconds after the register is reset to zero and before the next delivery is started, to allow an operator to detect any fault in a segment or in a circuit of the segment; or

  • (b) incorporate an automatic self-testing system that checks the operation of all display segments prior to starting a delivery and, where a fault is detected, prevents the delivery.

• (2) Subsection (1) does not apply in respect of secondary registers that display the same information as the primary register.

13. A register shall be designed so that the unit price cannot be changed while the register is computing the total price for a delivery.

14. A register shall be designed so that it automatically locks the register display and causes the liquid flow to stop where, during a delivery, false or missing pulses are detected that represent a quantity of liquid in excess of an amount that is the greater of

• (a) five times the applicable minimum increment of registration set out in section 20, and

• (b) one increment for every 1,000 increments registered during the delivery.