2.7.3. Operation with an external sensor. (Fig. 2.2)

In some instances, it might be desirable to use an external sensor to provide process information to the control circuitry in the flow controller. For example, you might want to control the pressure in a vacuum system by adjusting the rate at which the system is backfilled with a gas. The new, enhanced HFC series of flow controllers have provision for accepting a 0-5VDC output from an external sensor at pin 8 of the “Edge” connector. To activate this feature, the cover of the HFC must be removed to gain access to PC-888 and move a jumper on JP3. JP3 is a three pin jumper block located just below the “Edge” connector. In the normal operating mode, the jumper covers the bottom two pins. To select “External Sensor”, move the jumper to the upper two pins. This swaps the flow input to the controller circuit from the Flowmeter output to pin 8 of the “Edge” connector.

2.7.4. Soft Start

The response of the control circuit to sudden changes in the Command signal is set at the factory for fast, stable response and minimal overshoot. If any overshoot is a problem in a particular system, it is possible to slow down the controller response to sudden Command changes. Remove the outer cover from the instrument and remove pin jumper JP6 this will insert an R-C filter with a two second time constant into the command circuit. This will slow down the reaction of the controller to step changes in the Command signal and will ensure that there is no overshoot or undershoot in actual gas flow.

2.8.Range Changing:

The range of the flow controller can be changed in the field if recalibration facilities are available. The flow controller may require a different orifice and different laminar Flowmeter element (shunt), which can be purchased separately from the factory. A listing of the orifices and shunts are available and their flow rates can be found in Section 4.8.

The range of the small tube shunts can be changes by changing the front disk, consult factory for more information on disk options.

Figure 2.1

HFM-E-200/HFC-E-202

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Teledyne HFM-E-200, HFC-E-202 instruction manual Range Changing, Operation with an external sensor. Fig, Soft Start
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HFC-E-202, HFM-E-200 specifications

Teledyne HFC-E-202 and HFM-E-200 are advanced flow meters designed to provide precise measurement and monitoring of gas and liquid flows in various industrial applications. Both devices are engineered to meet the demands of sectors such as petrochemicals, pharmaceuticals, and food and beverage, where accuracy and reliability are paramount.

The Teledyne HFC-E-202 is a highly sensitive flow meter that utilizes a thermal mass flow measurement technology. This technology enables the HFC-E-202 to accurately measure the mass flow rate of gases regardless of temperature and pressure conditions. One of its key features is its ability to provide high precision and fast response times, making it suitable for applications that require immediate data feedback. The device is also equipped with advanced diagnostics that allow users to monitor the health of the system and identify potential issues before they escalate.

On the other hand, the HFM-E-200 is particularly renowned for its versatility in measuring both gas and liquid flows. It employs differential pressure technology, which is highly effective in a wide range of operating conditions. The HFM-E-200 incorporates a robust design that can withstand harsh environments, ensuring longevity and reliability. Its user-friendly interface allows for easy configuration and monitoring, catering to both novice and experienced technicians.

Both flow meters feature digital output options, facilitating seamless integration with existing control systems. This enables real-time data acquisition and monitoring, enhancing process control and efficiency. Furthermore, their compact design minimizes installation space, allowing for easy placement in tight operational areas.

In terms of safety and compliance, both the HFC-E-202 and HFM-E-200 are designed to meet strict industry standards, ensuring they can be deployed in critical applications without compromising safety.

In conclusion, Teledyne HFC-E-202 and HFM-E-200 flow meters stand out due to their innovative technologies, accuracy, and durability. Their unique features position them as essential tools for a variety of industrial sectors, enhancing operational efficiency and ensuring reliable fluid flow measurement. With Teledyne’s commitment to quality and innovation, users can trust that these devices will meet their demands both now and in the future.
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