Weigh platform operates in three modes

Edited by the Engineeringtalk editorial team Feb 9, 2006

Weigh platform has a flatbed design, a capacity of 120kg and an accuracy of 10g; its integral supply socket can be switched at a selected level to control external pumps and equipment.

The RDA Precision Weigh Scale from Datum Electronics has many uses, and is a popular option in the refrigerant handling industry.

The weigh platform has a flatbed design, a capacity of 120kg and an accuracy of 10g.

An integral supply socket can be switched at a selected level to control external pumps and equipment.

It also has the option of an electronic switch activated by a predetermined weight either on rise or fall.

This transfer control weigh platform was originally designed for the refrigeration industry, but the platform is also used in other simple fluid transfer and filling applications.

Maximum load capacity is up to 120kg with an adjustable trip point that can be set to operate rising or falling weight as desired.

It also has a full bridge centre point load cell and digital amplifier for high resolution and accuracy of indication.

The weigh scale can be used for on-site weighing as it has batteries that can be recharged from a mains power supply and a low profile robust steel construction in a durable industrial paint finish.

With touch pad controls and large digital LCD, it is easy to use and the unit can toggle the display to read either kg or lb/oz.

When recovering liquid refrigerant from plant or equipment, a recovery cylinder can fill rapidly.

For this reason, particularly with smaller cylinders, it is important to have accurate rapid response weight measurement.

The instrument samples three times every second, achieving a high accuracy of displayed weight and trip point operation.

For safety, it is not recommended to fill refrigerant cylinders to more than 60% of the full capacity to allow a vapour space for expansion.

The only safe method of determining the amount of refrigerant or pressurised product contained in a cylinder is by measurement of gross weight; calculate the maximum allowable gross weight by addition of the container tare weight and the maximum net fill stenciled on the container.

The scale may be operated in one of three modes.

In basic scale mode, the scale will display the gross weight of cylinders placed on the platform either when connected to the mains or powered by an integral battery.

The weight of refrigerant in cylinders or product in partially filled containers can thus be ascertained.

Automatic trip on rise in weight mode is used when operating the scale with a refrigerant recovery unit or a pump.

The recovery unit or pump is powered via the mains socket on the fascia and the cylinder is placed on the platform.

The operator can pre-set the switching point so the mains supply to the socket switches at the safe weight limit for the cylinder.

Where it is not practical to terminate flow by switching off power to the recovery unit or pump, the weigh scale can be used to power a normally closed solenoid valve in the supply line to the cylinder.

Automatic trip on fall in weight mode lets the weigh scale be used to control accurate charging applications or for controlling the transfer of product between cylinders.