The PPM Technology interface board (ifB) has been designed to connect the Formaldemeter to third party systems. The interface board can be configured to give different voltage outputs; a 4–20mA current output and also give a relay alarm output. Various modes of operation are available to suit a whole array of uses, applications and situations.

There is a configuration menu available to allow the user to choose output type, operation mode, select output tests, sampling range and also calibrate the Formaldemeter. The menu also alows for the incorporated voltage-less relay to be triggered at various concentrations so that external equipment can be controlled.

Typical Uses:

• Simple integration into exisiting sensor networks
• PLC control systems
• Stand–alone area monitoring
• Cleanrooms; Packing rooms & Workshops
• Single-point remote monitoring

The PPM Technology interface board (ifB) comes complete with the Formaldemeter htV and is fully calibrated and ready to use. Simply connect your external ouputs up to the ifB and switch on.

Modes of Operation

The ifB can be used in one of three sampling modes, depending on what best suits your needs. These are:

• Polled mode
In this mode samples are only taken when a valid pulse is detected on the sample input line. If the instrument has not cleared sufficiently to sample at this point then the sample will be delayed — as soon as the instrument is ready then a sample will be taken. This is ideal for use with PLC or other controller based systems as the sampling rate is controlled by the input lines and the current status is available as logic levels on the output lines.

• Continuous mode
This mode does not require any external trigger for sampling. Samples are taken as often as possible by the Formaldemeter. The sampling duration would be dependant on sample concentration (higher concentration samples will take longer to clear and will delay the next sample). This mode is easy to setup and is ideal for applications where no controller based systems are available and the sampling frequency can vary.

• Timed mode
This mode does not require an external trigger but unlike the previous continuous mode it uses an internal timer to trigger samples at a set frequency. This can be adjusted by the user between 1 and 60 minutes in increments of a single minute. However, the sampling frequency is not guaranteed as samples may be delayed if the Formaldmeter is not ready to sample at the designated time.

Sample, Data & Error