EU RO Mutual Recognition Group

General description of the product

a) Remote indicators of steam boiler water level, of the "indirect reading design" type. They can be based on different working principles and technologies, such as, for example:

- Conductivity Probes

- Differential Pressure Transmitters

- Magnetic Float Indicators

- Guided Wave Radar Level Indicators

b) Regardless of technology, their basic configuration includes:

- one or more sensing devices, appropriately connected to the boiler drum (either directly or through an externally located measuring vessel, such as a water column); the sensing devices can be totally or partly immersed in the steam-water space;

- a transmitter (usually converting the original signal into the 4-20 mA analogic format);

- a remote level display.

c) Regardless of technology, the devices normally include some means for correction of density error, generated by difference of temperature between the water in the drum and that contained within a measuring vessel located externally at the boiler drum (e.g. the water column), due to sub-cooling of water in the measuring vessel.

d) The pressure vessels containing the sensor(s) (e.g. externally located measuring vessels, water column or equivalent) are outside the scope of the present Technical Requirement.

e) Level indicators of the direct reading type (such as reflex gauges, flat glass gauges, ported gauges and similar devices) are outside the scope of the present Technical Requirement.

f) The equipment for control of the boiler (e.g. water level control, pressure control, temperature control) is subject to individual EU RO approval and is outside the scope of this Technical Requirement.