48.—(1) In addition to the requirements set out in paragraphs 44 and 45, the following specific requirements shall apply in relation to discontinuous totalisers.
(2) Accuracy Classes
Discontinuous totalisers are divided into four accuracy classes, as follows—
(i)0.2;
(ii)0.5;
(iii)1; and
(iv)2.
(3) MPE
| Accuracy class | MPE of Totalised load |
|---|---|
| 0.2 | ±0.10% |
| 0.5 | ±0.25% |
| 1 | ±0.50% |
| 2 | ±1.00% |
(4) Totalisation scale interval
The totalisation scale interval (dt) shall be in the range:
0.01 % Max ≤ dt ≤ 0.2 % Max
(5) Minimum Totalised Load (Σmin)
The minimum totalised load (Σmin) shall be not less than the load at which the MPE is equal to the totalisation scale interval (dt) and not less than the minimum load as specified by the manufacturer.
(6) Zero Setting
Instruments that do not tare weigh after each discharge shall have a zero setting device. Automatic operation shall be inhibited if zero indication varies by—
(a)1 dt on instruments with automatic zero setting device; or
(b)0.5 dt on instruments with a semi-automatic, or non-automatic, zero setting device.
(7) Operator Interface
Operator adjustments and reset function shall be inhibited during automatic operation.
(8) Printout
On instruments equipped with a printing device, the reset of the total shall be inhibited until the total is printed. The printout of the total shall occur if automatic operation is interrupted.
(9) Performance under influence factors and electromagnetic disturbances
(a)The MPE due to influence factors shall be as specified in Table 13.
| Load (m) in totalisation scale intervals dt | MPE |
|---|---|
| 0 < m ≤ 500 | ±0.5dt |
| 500 < m ≤ 2 000 | ±1.0dt |
| 2 000 < m ≤ 10 000 | ±1.5dt |
(b)The critical change value due to a disturbance is one totalisation scale interval for any weight indication and any stored total.