Incorporating either 2 or 4 columns, dependent on the required output flow, these on-line dryers switch between duty and regeneration columns, thus ensuring that the desiccant is always in its best possible condition and dry gas is delivered, automatically, on 24/7 basis.

The CODD offers the following advantages:

• Provision of a reliable zero reference or blanketing purge gas, essential for the integrity of any process where the presence of moisture can be critical.
• Purging hygrometers with a dry gas stream when not being used on process will help to maintain the sensors in best condition and guarantee fastest response when sample measurements are required.
• operator can validate the performance of any hygrometer, on demand. The operator can quickly and easily check the response speed and sensitivity of the analyser. Detailed data record-keeping can help to identify if the performance of the hygrometer deteriorates. See MCM Validation System.
• The mean service interval of a hygrometer can be extended by purging with ‘dry’ gas when the instrument is not being used.
• No user interface is required – the dryer operates fully autonomously, with automatic regeneration of the desiccant.
• The desiccant can aid in removing light contaminants – ideal for purging portable hygrometers used for spot-checking measurement of hydrocarbon streams.

For applications where a fixed installation dryer is not practical, MCM’s Bottled Gas Dryer (BGD) offers a portable ‘dry’ gas source, also certified to <-75°C Dewpoint. Featuring a single column, the BGD has no day-to-day power requirement and is therefore an ideal tool for work in hazardous areas, or where flammable gases must be dried (e.g. hydrogen or natural gas). The compact dimensions and low weight make the BGD transportable around any operating plant.

With the same advantages as the CODD, it is recommended that clients always use a BGD for portable moisture analysis applications where contamination in the gas stream may degrade the performance of the sensor (e.g.: petrochemical applications). A BGD offers an extremely cost-effective method of checking for contamination and drift of the instrument’s zero point.