Dwyer Series 3100D Explosion-Proof HART DP Transmitter

Series 3100D explosion-proof differential pressure transmitter with HART

The Dwyer Series 3100D is a microprocessor-based smart differential pressure transmitter in an explosion-proof, NEMA 4X (IP66) housing. It outputs 4-20 mA with HART communication, can be configured from the zero and span push buttons without a calibrator, and offers a stated accuracy of ±0.075 % of full scale with 100:1 rangeability. The datasheet lists applications in flow measurement, level monitoring, filter or pump differential pressure and critical process monitoring.

Seven Star LLC supplies the Series 3100D in Oman and the GCC as an independent supplier in Muscat. The sections below set out the ranges, the ordering code structure and the approval information that is actually printed on the manufacturer datasheet, so that a purchase specification can be checked against project requirements.

Series 3100D model chart and ordering code

Standard stocked-type models are written as 3100D-2-FM-1-1, with an optional -LCD suffix for the five-digit display. The range digit selects the calibrated span: 2 for 0.6 to 30 in w.c., 3 for 1.5 to 150 in w.c., 4 for 7.5 to 750 in w.c., 5 for 1 to 100 psi and 6 for 3 to 300 psi. The full ordering example on the datasheet adds range 1 (0 to 6 in w.c.) and range 7 (0 to 1000 psi), the approval code FM or WP (weatherproof only, with a 316 SS housing), the process connection (1 for 1/4 in female NPT or 3 for diaphragm seal), and the electrical connection (1 for 1/2 in female NPT).

For diaphragm seal versions the code continues with the seal type (extended or flush, direct mount or capillary), flange size 2 or 3 in, flange rating (ANSI 150 or 300, DIN PN 10/16 or 25/40, JIS 10K or 20K), extension length, diaphragm material (316L SS, PTFE with 316L SS, Hastelloy C-276 or tantalum), fill fluid (silicon oil, -40 to 400 °F), capillary lengths of 0 to 20 ft and options such as custom calibration, NIST calibration, LCD and 316 SS housing.

Technical specifications of the Series 3100D

How the Series 3100D measures and communicates

A pressure sensor in the high and low side process chambers produces a signal that is digitized and compensated for temperature by the transmitter software. The sensor correction coefficients and the user configuration are stored in EEPROM, so after a shutdown or a loss of power the instrument restarts with its settings. The result is converted to a 4-20 mA signal, with HART digital communication superimposed.

On site the zero and span buttons set the 4 mA and 20 mA points against applied pressure, and the HART interface permits changes of engineering units, damping, output (linear or square root), display mode and custom ranges. Square-root output makes the transmitter directly usable with an orifice plate or other differential-producing element for flow, and the long list of engineering units on the datasheet covers volumetric and mass flow units as well as level and pressure units.

Because it is a DP unit, the same transmitter can monitor differential pressure across a filter or pump, or hydrostatic level in a closed vessel using the high and low side connections.

Placing the Series 3100D next to its siblings

The Series 3200G is the gauge-pressure version of the same platform with a 1/2 in process connection and wider upper limits to 8500 psi. The Series 3100D is selected when a differential signal is required: flow with a primary element, level in closed tanks, or filter condition. For HVAC and clean air duties, lower cost non-explosion-proof units such as the Series 616KX, 616W and 616D are available from the same maker.

On the control side a HART-capable analog input, or a K-System transmitter supply such as the KFD2-STC5-1 where an isolated interface is needed in a non-hazardous marshalling area, completes the loop.

Selection and ordering checklist for the Series 3100D

• Calibrated span and range code, including the units required
• Process connection: 1/4 in NPT or diaphragm seal, and the seal type, flange, material and fill fluid
• Approval: FM or weatherproof only; confirm that the project area classification (for example Zone-based approvals) is satisfied, since the datasheet lists FM and CE only
• Electrical connection and need for the LCD
• Configuration needs: custom calibration or NIST certificate
• Power supply of 11.9 to 45 V DC and loop resistance for HART

Installation, calibration and maintenance of the Series 3100D

Mount the transmitter with the manifold or block valves to be used for isolation and venting; the datasheet lists a two-valve block manifold as an accessory for the 3200G, and the 3100D has 2 drain valves. Connect the high and low sides to match the polarity of the measurement and wire the loop with shielded cable through the two 1/2 in conduit entries.

Zero the instrument under static conditions with equalised pressure on both sides, then set the span. Because the zero shift from the mounting orientation and from the fill-leg weight of capillary seals can be significant on low ranges, perform the final zero on site. Keep a record of configuration and calibration dates, and use the NIST calibration option where traceability is required.

Typical applications in Oman and the GCC

The 3100D is a typical choice for flow measurement with orifice plates, for level in closed or pressurised vessels, and for filter and pump differential pressure monitoring in oil and gas, petrochemical, power and desalination plants. Where hot ambient temperatures prevail, check the upper ambient limit of 185 °F (85 °C) without display and 176 °F (80 °C) with display against radiant heat and solar loading on outdoor installations.

Series 3100D range options

Range codes of the standard models, from the manufacturer model chart.

Information to send with an RFQ for the Series 3100D

Please send these items with the enquiry.

• Measured fluid, process temperature and static pressure
• Required calibrated range and units, and whether square-root output is wanted
• Process connection or diaphragm seal details
• Approval and area classification required
• Quantity and delivery date

Documents and quotation

The manufacturer datasheet for the Series 3100D is attached on this page, so the electrical data, terminal assignment and ambient limits quoted above can be checked against the original document before an order is placed.

Seven Star LLC supplies Dwyer products in Oman and the GCC as an independent supplier in Muscat. Send the quantity, the signal types and the project delivery date, and we will confirm availability and lead time in a written quotation.