Chapter 3 Operation

Series 830/840/860 Instruction Manual

 

 

Mass Flow Controller Features

Over-Range and Cold Sensor Lockout Circuit

Side-Trak Models incorporate an over-range circuit which disables the output signal when the sensor is heating to its normal operating range, or if an over flow condition exists. The operation of this cir- cuit can be verified by observing the 5 VDC (20 mA) output signal during power up.

The cold sensor lockout safety circuit automatically closes the valve if a fault condition is detected that could result in uncon- trolled flow (valve wide open). The circuit operates by monitoring the temperature of the sensor elements. If the temperature falls be- low a preset limit the circuit forces the output signal to a fixed high level which disables the output signal. The cold sensor lockout cir- cuit is enabled during initial start-up. This feature is not available if liquid is present in the flow path.

There are several conditions which could trigger the cold sensor lockout circuit:

1.Operation at a temperature below the instrument’s rating.

2.Power failure while running at or near full scale. Upon resump- tion of power, the valve will remain closed until the minimum operating temperature is again reached.

3.Sensor failure.

If needed, the cold sensor lockout circuit and/or over-range indicator can be disabled by removing CR1 from the main 830 circuit board.

Controller Auto Shut-Off Feature

All flow controllers are normally provided with an Auto Shut-Off feature that closes the valve at a command signal level of approxi- mately 2% of full scale, or less. (All electromagnetic valves fail normally-closed). On 840 controllers, this value can be reduced. Contact the factory for details on this option.

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Sierra 840 Mass Flow Controller Features, Over-Range and Cold Sensor Lockout Circuit, Controller Auto Shut-Off Feature
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840, 830, 860 specifications

The Sierra 860, 830, and 840 are a series of rugged outdoor laptops designed for professionals who require reliable and powerful computing solutions in challenging environments. These laptops combine advanced technologies and robust construction to meet the demands of various fields, including engineering, military, field services, and outdoor research.

One of the standout features of the Sierra series is its rugged design. Constructed with military-grade materials, these laptops are highly resistant to shock, vibration, and extreme temperatures. They have undergone rigorous testing according to MIL-STD-810G standards, which ensures they can withstand harsh conditions whether in the field or during transport. Additionally, the IP65 rating guarantees protection against dust and water exposure, making them invaluable for professionals working in inclement weather or dusty environments.

The Sierra 860, 830, and 840 are powered by high-performance processors, delivering fast and efficient processing capabilities. Equipped with the latest Intel Core processors, including i5 and i7 options, these laptops can handle demanding applications and multitasking with ease. The robust memory options, ranging from 8GB to 32GB, ensure smooth performance for memory-intensive tasks.

Display quality is another critical aspect of these laptops. The Sierra series features high-resolution screens that offer bright, vivid colors and sharp details, making them ideal for tasks requiring precision, such as drafting and design work. The touch-enabled displays enhance user interaction, providing convenience in outdoor settings where traditional input methods may be challenging.

The Sierra laptops also include a comprehensive array of connectivity options, ensuring seamless integration with various devices. With multiple USB ports, HDMI output, and optional mobile broadband, users can easily connect to peripherals, transfer data, and maintain communication. The inclusion of enterprise-level security features, including biometric scanners and encrypted storage, ensures sensitive data remains protected.

Battery life is another crucial factor in fieldwork, and the Sierra series excels in this area. With long-lasting batteries, these laptops can operate for extended periods without needing a recharge, making them perfect for long outdoor excursions or remote job sites.

In summary, the Sierra 860, 830, and 840 combine ruggedness, high performance, and extensive connectivity options, making them exceptional computing solutions for professionals in various challenging environments. Their advanced technologies and robust constructions ensure they can tackle the demands of outdoor work while maintaining reliability and efficiency.
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