ISO 12809:2020 pdf free.Crop protection equipment -Reciprocating positive displacement pumps and centrifugal pumps一Test method.
4 Accuracy of measurements
Temperatures shall be measured with a maximum error of ±1 °C.
Length shall be measured with a maximum error of ±1 mm.
Suction pressure shall be measured with a maximum error of ±2 kPa.
Delivery pressure shall be measured with a maximum error of ±1 %.
Rotating speed shall be measured with a maximum error of ±1 %.
Flow-rate for stand-alone pumps according to 22 shall be measured with a maximum error of ±1,5 %.
Flow-rate for pump installed on a sprayer as in ZL3L shall be measured with a maximum error of ±2 % of the measured value when the flow-rate of the pump is >100 1/mm, and ±2 1/mm when the flow-rate of the pump is >100 1/mm.
Load torque shall be measured with a maximum error of ±5 %, at least for values greater than the 25 % of the maximum torque.
The time measurements shall be made to an accuracy of ±1 s, with the exception of measurement indicated in 7.2.7.2 and 7.2.8.2 for which the accuracy shall be of ±0,05 s.
7.2.1.1 The test bench shall have a main circuit containing the devices for flow control and pressure adjustment; see Figure 1 with the scheme of hydraulic circuit for self-priming pump or Figure 2 with the scheme of hydraulic circuit for non-self-priming centrifugal pump. To simulate the installation of positive displacement pump on the sprayer, the test bench shall have an extra circuit (key A in Figure 1) with part of the flow coming back directly to the suction line of the pump.
7.2.1.2 The suction line connects the pump with the tank. It shall be fitted with an air inlet valve (key
4 in Figure 1 or Figure 2), a suction pressure adjustment valve (key 6 in Figure 1 or key 5 in Figure 2) and a suction pressure gauge (key 7 in Figure 1 or key 6 in Figure 2). For self-priming pumps, the h value shall be (400 ± 100) mm (Figure 1). For non-self-priming pumps, the h value shall be (—400 ± 100) mm (Figure 2). The inlet of the suction line shall be free, without non-return valves.
7.2.1.3 The delivery line shall be fitted with a safety valve (key 9 in Figure 1) with appropriate range able to protect the test bench, a pressure gauge (key 10 in Figure 1 or key 8 in Figure 2), a device for flow- rate measurement (key 11 in Figure 1 or key 9 in Figure 2) and a pressure adjustment valve (key 12 in Figure 1 or key 10 in Figure 2). The output of the delivery line shall be connected to the tank in order to guarantee the re-circulation of the test liquid (key 13 in Figure 1 or key 11 in Figure 2). Ensure that the back flow does not create turbulence in the suction line.
7.2.1.4 The extra circuit (key A in Figure 1) shall be fitted with a re-circulation adjustment valve (key
14 in Figure 1) and a shut-off valve (key 15 in Figure 1) able to isolate this part of the circuit.
7.2.1.5 The level of the liquid in the tank (key 2 in Figure 1 or Figure 2) shall be equal (±10 mm) to the top of the pump housing at the beginning of the test. Set the level when all the lines are filled with the test liquid. During the measurement, the level of the liquid in the suction tank shall not change by more than ± 50 mm.ISO 12809 pdf download.