The Pharmagraph VF8023 module drives a single air sampler and has inputs for control of the ‘Run’ and ‘Gas’ activities and outputs to indicate ‘Running’ and ‘Fault’ states. While ‘Run’ is asserted, the module controls the fan and drives the ‘Running’ output to show this. When the programmed sample duration has elapsed, the Air Sampler drive output turns off and the ‘Running’ status is negated. The ‘Gas’ input can be used to drive the Air Sampler so that the head can draw gas through the unit during sanitisation. The output remains on until the input request is turned off. The fan drive voltage, current and fan speed are constantly monitored, and the ‘Fault’ output is asserted if any of the monitored parameters is outside the permitted limits.
- Controls a single Air Sampler
- Monitors and controls air flow rate
- Programmable sample duration and flow rate
- Supports continuous or intermittent sampling
- Internally monitors fan drive voltage and current
- Out of limits alarms for drive voltage, current and fan speed
- 4-20mA output indicates sample progress
- Host communications with ModBus RTU interface
- Aux RS485 for use in fault-tolerant systems
- Digital I/O for stand alone control
The VF8023 offers continuous or intermittent sampling operation to draw an accurate cubic meter sample of air over the sample plate. With continuous sampling the VF8023 automatically runs the fan until the entire cubic meter sample has been drawn in a single operation. Intermittent sampling offers a programmable number of shorter samples spread over a longer period to make up the 1 cubic meter volume. For example, a series of 1-minute long samples (100l) drawn every 15 minutes would allow a cubic meter sample to be spread over 2.5 hours. Intermittent sampling is often used to reduce the number of interventions during a production process.