The present invention relates to a pressurised gas cylinder.

Such cylinders are known for a wide range of applications where a piped gas supply is not available.

In order to measure information on the content of the cylinder, for example, pressure, impurities, polymerisation, composition, temperature etc., this has to be done via sensors which are provided in a port through the cylinder wall or via the housing of the valve assembly which is present on the top of the cylinder. This means that dedicated hardware either in the form of a modified valve or a modified cylinder is needed. It is not therefore possible to monitor pressure of a gas cylinder which is already in service without changing the cylinder or the valve.

According to the present invention there is provided a pressurised gas cylinder according to claim 1.

The acoustic transmitter from the module which is in contact with an internal wall of the cylinder provides a way of getting information out of the cylinder without requiring a physical port. Further, the use of an acoustic signal to achieve this is a solution which will work with metal cylinders where it is not possible to use an electromagnetic system due to the shielding properties of the metal.

The sensor may include a pressure sensor and/or a temperature sensor. It may include additional sensors such as accelerometers, moisture-, CO2-, or O2-sensors.

The module may be formed integrally with the cylinder body or may be inserted through some other opening in the cylinder body. However, preferably, the cylinder has a neck with an opening to receive the valve and the module is small enough to be insertable through this opening. This provides a simple way of applying the module to existing cylinders without the need to change the cylinder or the existing valve assembly.

The module may simply be dropped into the cylinder so that it is in contact with the bottom wall. However, preferably the module further comprises an attachment means to attach the module to the internal wall of the cylinder. The attachment means may be a mechanical mounting or a tacky surface to adhere to the cylinder wall. However, preferably, the module is provided with a permanent magnet by which it attaches to the internal cylinder wall.

The second transmitter may have a display to display the sensed data. However, it preferably additionally or alternatively has a second transmitter in order to transmit the information received from the acoustic transmitter to a remote location.

An example of a cylinder in accordance with the present invention will now be described with reference to the accompanying drawing which is a schematic cross-section of the cylinder.

The cylinder 1 is a standalone gas cylinder typically used in various fields including medical and industrial fields to supply bottled gas to a user when a piped gas supply is not available. The cylinder will typically have a maximum pressure of up to 400 bar. The cylinder comprises a cylinder body 2 and a valve assembly 3 both of which are conventional. The improvement provided by the present invention is the addition of a sensor module 4 and its associated receiver 5. The sensor module comprises a magnet 6 which will adhere to the bottom wall of the cylinder body 2 provided that this is a ferrous material. The sensor also comprises a battery 7, pressure and temperature sensors 8 and a transmitter 9. The module 4 preferably has the ability to fit through a circular opening with a diameter of 20mm and more preferably has the ability to fit through a circular gap with a diameter of 12mm. The sensor module can therefore be dropped in through the neck 10 of the cylinder body 2 before the valve assembly 3 is screwed into place in the neck 10.

More specifically, the sensor module 4 includes a sound encoder and transmitter to send an acoustic signal via the wall of the cylinder body 2. The information is modulated on a carrier signal using, for example, AM, FM, QAM or other technologies. The receiver 5 then extracts the information from a carrier signal using a decoder and converter.

The transmitter 9 of the module 4 transmits data concerning the pressure and temperature to the receiver 5. This is provided with a decoder, processor, display and/or second transmitter to transmit information to a remote location (e.g. via Bluetooth, NFC or GMS).