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July 1, 1999

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Product News - Instrument News: Heaterless Injection Nozzles, 'Smart' PressureTransmitters, Portable Pressure Sources

Instrument News: Heaterless Injection Nozzles, 'Smart' Pressure Transmitters, Portable Pressure Sources

pn24-799.jpgDynisco Instruments has introduced three new products: a series of heaterless injection machine nozzles that are designed with ad-vanced heat pipe technology; a series of smart, multi-variable pressure transmitters, and a line of portable pressure sources.

Injection machine nozzles, designed with advanced heat pipe technology, are said to provide improved temperature consistency as well as to reduce down time due to changing the number of heater bands required from several to just one.

Other benefits attributed to heat pipe technology are the ability to use longer nozzles with deeper mold reach without sacrificing melt quality, as well as the  elimination of additional electrical hazards near the operator.

This nozzle can be ordered as a 'smart' nozzle by equipping it with a pressure transducer mounting hole. This is said to provide an optimum point to measure actual real-time pressure that is critical to the injection machine's ability to optimize the process via decisions made by its control system.

The mounting hole can be filled with any of the manufacturer's nozzle pressure transducers. Examples of the transducers designed for this hole are both the strain-gage and amplified versions of the PT465, PT465XL and the PT467.

Prices range from $725 to $1995, depending on the models and options chosen. 

PN 25-7/99Multi-variable pressure transmitters are designed for pressure measurement of high-temperature processes. According to Dynisco, this instrument will provide two measurements (process pressure and temperature) with only one intrusion into the process.

In addition, using these transmitters is said to eliminate the guess-work of adjusting control loops for the effects of temperature on the pressure measurement whenever process changes are made that affect operating temperature.

The IPX and PX series are claimed to self-correct their pressure measurement for process and ambient temperature effects, maintaining up to 0.15% (0.25% for the PX series) pressure measurement accuracy at process temperatures from 77 to 662 F.

Conventional 'smart' process transmitters are said to be limited to operation at process temperatures of less than 212 F and their performance accuracy decreases as process temperatures increase.

The new transmitters are able to do this because they use a new thin-film element and proprietary processing methods to produce an 'ultra-stable' pressure measurement. Current micro- processor-based circuit technology and proprietary software algorithms digitize the pressure measurement and correct for process temperature effects.

Other benefits cited include:

  • Pressure measurement at pressures of 750, 1500, 3000, 5000, 7500 and 10,000 psig.

  • No calibration. By eliminating the need to fine tune set-point online, these units can increase yields and reduce scrap and labor expense.

  • Reduced transmitter inventory. One transmitter can operate at several pressure ranges because they have a span-turndown ratio of up to 5:1 means.

  • Accessibility from remote locations. The HART1 communicator can be attached to the 4-20 mA signal loop at any convenient location, enabling transmitter adjustments and diagnostics from the control room or other remote locations.

  • Easy installation. Units are available in a variety of mounting configurations, including the process industry standard remote diaphragm seal, threaded, flange and other custom configurations.

  • Dual line display shows both process pressure and process temperature at the same time. This can improve safety by reducing the number of instruments and process connections.

The IPX and PX series of transmitters are priced around $2000.


A note about HART protocol: HART stands for Highway Addressable Remote Transducer. It is a protocol that provides a standard twisted pair of wires with a 4 to 20 mA signal and digital capabilities for up to 15 additional signals (analog and digital) over the same twisted pair with two-way communication.

Benefits cited by the HART Communication Foundation include reduced wiring and installation costs for savings of $200 to $500 per installation, maintenance savings of $100 to $200 per unit, interoperability with multiple suppliers and remote diagnostics.

PN 26-7/99Portable pressure sources, the PPS1100 and PPS1200, allow users to calibrate their melt pressure transducers off line with an accuracy of ±0.1%. The PPS1200 can simulate actual process temperatures up to 752 F due to its heat pressure port and built-in  PID temperature controller.

Both units also allow zero and span adjustments to be made off line so the process and/or machine do not have to be shut down. This can save production time and money, especially for processes that are always under pressure.

The PPS1100 and 1200 are capable of pressure up to 10,000 psi and are switch-selectable between psi, bar and kPA. Measurements are indicated on a battery-operated LCD.

Pressure is applied by a large knob that is attached to a mineral oil-filled reservoir, thus creating pressure inside the 1/2-in. standard pressure port. Both units eliminate the need for the user to keep 'dead weight testers' for transducer calibration and set-up.

Units are also equipped with a standard serial communications port. Prices start at $2500. Options include data analysis software and cable for data transfer and storage. Up to 900 measurements can be stored.

Dynisco Instruments
Sharon, MA

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