The intervals on the scale depend on the model and total length of the product you select.

In the case of the products with a description of "Effective Scale: 10:1" in the specification sheet of the catalog,
the measurement range is from 10 to 100% of the specified maximum flow rate.
The measurement range of the other products is the same as the flow rate range specified in the specification sheet of the catalog.

Please specify the pressure applied to the primary side of the flow meter as the supply pressure and the downstream pressure applied to the secondary side of the flow meter as the outlet pressure.
For example, if the flow meter has a regulator at the upstream part, the supply pressure should be the set pressure of the regulator. If the downstream part of the flow meter is exposed to the air and no other pressure is applied, the output pressure is zero.

In the case of gas, the measurement pressure is the atmosphere pressure if the secondary side is exposed to the air and no other pressure is applied to the flow meter.
If any pressure is applied to the flow meter, for example, when the flow meter has a valve at the secondary side, the pressure value should be the load pressure.
Please note that a negative pressure that is lower than the atmosphere pressure cannot be specified as the measurement pressure.

Please tell me the serial number on the label.