DMP331 Precision Pressure Transmitter

DMP331 Precision Pressure Transmitter

Stainless steel pressure transmitter with ranges from 100mbar up to 40 bar gauge or absolute with optional accuracy ranging from the standard 0.35% FS up to 0.1% FS.  Special options such as ATEX/IECEx approval, SIL approval and compound ranges are also available.

Product Parameters

  • Pressure Range: 0 to 0.1 up to 40 bar g, abs, compound and negative gauge
  • Accuracy: 0.35%, 0.25% or 0.1% FS
  • Output Signal: 2 wire 4-20mA, 3 wire 0-20mA or 0-10Vdc
  • Electrical Connections: DIN plug, Binder, M12, IP67/68 cable gland or field housIng
  • Pressure Connectors: 1/4 BSP male DIN3852 or EN837, 1/2 BSP male DIN3852, EN837, flush or open port, 1/4 NPT male, 1/2 NPT male, M10 male and M12 male
  • Media Compatibility: SS316L diaphragm and process connection with FKM, EPDM or all welded seals.
  • Media Operating Temperature Range: -40 to +125 degC
  • Special Options: ATEX and IECEx Intrinsic safety gas or dust, Baro and Compound ranges, SIL2 Approved electronics
  • Weight: ~140 g
  • Dimensions: 26.5 mm diameter

Product Description

The DMP 331 precision pressure transmitter is a silicon strain gauge based sensing device with high repeatability and low pressure hysteresis measurements. The silicon chip is isolated from the pressure media by a thin stainless steel membrane and silicone oil fill.

The high sensitivity of silicon semiconductor strain gauges facilitates low pressure ranges down to as low as 0 to 100 mbar and because of the metal capsule construction it is compatible with wet media.

The electronics offer flexibility of output along with improved linearisation options for better measurement accuracy.

The DMP331 has been hazardous zone approved for use in work areas that may contain flammable or dusty atmospheres. There is also the option for SIL2 approved electronics where more stringent reliability and safety is required.

Product Applications

Biodiesel tank contents

Measure the level of biodiesel with this hydrostatic pressure transmitter.

  • SKU ID: s1-dmp331-0011
  • Part No: 110-1600-1-5-100-H00-1-000
  • Pressure Range: 0 to 0.16
  • Units: bar
  • Range Type: Positive Gauge (atm to +P)
  • Output Signal: 4-20mA (2 wire)
  • Accuracy: 0.5% (11-12bit resolution)
  • Electrical Connection: DIN43650A plug IP65
  • Process Connection: G1/2 DIN3852 male open port
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM

Smokestack atmospheric pressure

Current-output barometric pressure sensor to measure the pressure of the atmosphere around a coal-fired smokestack.

  • SKU ID: s1-dmp331-0002
  • Part No: 111-1601-1-3-TAO-N40-1-000
  • Pressure Range: 1.6 bar abs
  • Output Signal: 4-20mA (2 wire)
  • Accuracy: 0.35%FS (std, 11-12bit res)
  • Electrical Connection: IP67 seal with 2m of cable
  • Pressure Connection: 1/4 NPT male
  • Media Exposed Seals: FKM (standard)

Fire suppression water pressure

ATEX approved 4-20mA pressure transmitter to measure water pressure in an automatic fire suppression system.

  • SKU ID: s1-dmp331-0003
  • Part No: 110-1502-E-3-TA0-N40-1-000
  • Pressure Range: 0 to 15
  • Units: bar
  • Range Type: Positive Gauge (atm to +P)
  • Output Signal: 4-20mA, ATEX / IECEx IS, (2 wire)
  • Accuracy: 0.35%FS >= 0.4 bar, 0.5% < 0.4bar (11-12bit resolution)
  • Electrical Connection: DIN43650A plug IP65
  • Process Connection: G1/2 DIN3852 male
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM

Environmental monitoring

800-1200mbar sensor, with 4-20mA output to be used on environmental monitoring installation.

  • SKU ID: s1-dmp331-0004
  • Part No: 111-B200-1-3-100-100-1-000
  • Pressure Range: 800 to 1200 mb abs
  • Output Signal: 4-20mA (2 wire)
  • Accuracy: 0.35%FS (std, 11-12bit res)
  • Electrical Connection: DIN43650A plug IP65
  • Pressure Connection: G1/2 DIN3852 male
  • Media Exposed Seals: FKM

Landfill gas collection

Monitor the low pressures  generated by gas recovered from landfill sites.

  • SKU ID: s1-dmp331-0005
  • Part No: 110-9999-E-5-TAO-N40-1-000
  • Pressure Range: 0 to 75″ H20
  • Units: inches water column
  • Range Type: Negative Gauge/Suction (atm to -P)
  • Output Signal: 4-20mA, ATEX / IECEx IS, (2 wire)
  • Accuracy: 0.5% (11-12bit resolution)
  • Electrical Connection: IP67 seal with 2m of cable
  • Process Connection: 1/4 NPT male
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM

LPG pressure reducing stations

Measure the pressure of liquid petroleum gas on pressure reducing stations in a ATEX approved hazardous area zone.

  • SKU ID: s1-dmp331-0007
  • Part No: 110-3000-E-5-TA0-400-1-000
  • Pressure Range: 0 to 300
  • Units: mbar
  • Range Type: Positive Gauge (atm to +P)
  • Output Signal: 4-20mA, ATEX / IECEx IS, (2 wire)
  • Accuracy: 0.5%FS (11-12bit res)
  • Electrical Connection: IP67 seal with 2m of cable
  • Process Connection: G1/4 EN837 male
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM
  • SKU ID: s1-dmp331-0008
  • Part No: 110-4001-E-2-TA0-400-1-000
  • Pressure Range: 0 to 4
  • Units: bar
  • Range Type: Positive Gauge (atm to +P)
  • Output Signal: 4-20mA, ATEX / IECEx IS, (2 wire)
  • Accuracy: 0.25%FS (11-12bit res)
  • Electrical Connection: IP67 seal with 2m of cable
  • Process Connection: G1/4 EN837 male
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM
  • SKU ID: s1-dmp331-0009
  • Part No: 110-2002-E-2-TA0-400-1-000
  • Pressure Range: 0 to 20
  • Units: bar
  • Range Type: Positive Gauge (atm to +P)
  • Output Signal: 4-20mA, ATEX / IECEx IS, (2 wire)
  • Accuracy: 0.25%FS (11-12bit res)
  • Electrical Connection: IP67 seal with 2m of cable
  • Process Connection: G1/4 EN837 male
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM

Product Help

Output response

What is the measurement response of the DMP331?

  • 2-wire: ≤ 10 msec
  • 3-wire: ≤ 3 msec

Resolution of output signal

What is the resolution of the output signal from the DMP311 precision pressure transmitter for the different accuracy options available?

The DMP331 with the accuracy option of 0.35% FS or 0.25% FS IEC60770 accuracy has a resolution of 11 to 12 bits, 2048 to 4096 steps or 0.04882% to 0.02441% span.

The accuracy option 0.1% FS IEC60770 has a resolution of 14 bits, 16,384 steps or 0.0061% span.

Missing 0.2%FS accuracy option

I normally purchase a DMP331 stainless steel pressure transmitter with the code B accuracy of 0.2% FS (IEC 60770), but I cannot find it mentioned on the specification data sheet, is it a specially requested option?

The DMP331 accuracy option 2 (code B) for pressure ranges ≥ 1 bar of ≤ ± 0.20 % FSO (IEC60770) ≤ ± 0.100 % FSO (BFSL) has been recently been made obsolete. Alternatively you can select the new more accurate option 2 (previously option 3)(code 1) of ≤ ± 0.1 % FSO for all pressure ranges or the slightly less accurate option 1 (code 2) for pressure ranges ≥ 0.4 bar: of ≤ ± 0.25 % FSO.

Overpressure effect on calibration

I am interested in the DMP331 pressure transducer for use on a pneumatic system. The 2.5 bar transducer has a rated over pressure of 10 bar, does this mean that if a pressure is applied between 2.5 and 10 bar, there will be no calibration shift of the transducer output signal? Do we need to install a solenoid valve to switch between the 2.5 bar range and a transducer with a range up to 10 bar, or can both transducers be connected permanently on the same measurement line?

You may experience some calibration shift depending on the amplitude, rate of change and duration of the over-pressure, but it should stay within the performance limits of the DMP331 specification:

  • Standard: nominal pressure < 0.4 bar: ≤ ± 0.5 % FSO, nominal pressure ≥ 0.4 bar: ≤ ± 0.35 % FSO
  • Option 1: nominal pressure ≥ 0.4 bar: ≤ ± 0.25 % FSO
  • Option 2: for all nominal pressure: ≤ ± 0.1 % FSO

The rating is intended for a temporary overpressure so we would suggest using a solenoid valve to protect the lower range sensor where an overpressure condition is expected to occur over a long duration or significant proportion of the transducer’s service life.

Voltage supply for ATEX IS 4-20mA signal

What is the input voltage for the DMP331 with 4-20mA output and ATEX IS approval?

Any voltage between 10-28Vdc between the connections to the transmitter.

Barometric scaling

What is different about the barometric version of the DMP331 compared to a standard pressure range?

To improve measurement performance of barometric measurements the 4-20mA output signal of a pressure transmitter is scaled from 800 to 1200 mbar absolute.

Typically a pressure transmitter is calibrated at 5 points over its range to ensure it is inside specification. If a 0 to 1 or 1.5 bar absolute range is used to measure the barometric pressure you will only be using the pressure transmitter over a narrow part of its range and most likely only 1 or 2 of the calibration points will be inside the barometric pressure range.

By scaling the current loop output signal of the absolute pressure transmitter to the barometric pressure range each of the 5 calibration points which are equally spaced between the lowest and highest measured pressure will be inside the region of barometric measurement and thus will provide a more robust verification of the pressure transmitter’s performance.

The effective increase in signal output over the barometric pressure range also allows the most use of the bit resolution available from the instrument measuring the output signal from the barometric pressure transmitter.

Trip alarm at 10 mb abs & atmospheric pressure

We have a vacuum drying process and need to trip alarms when the target vacuum of 10 mbar absolute is reached and when the vacuum chamber returns to atmospheric pressure so the operator knows when it the chamber is fully vented so that the lid can be opened easily. What instruments would you suggest to achieve this?

Our suggestion would be to use a low absolute reference range sensor such as the DMP331 to ensure the pressure goes below 10 mbar absolute, it’s lowest range is 0-100 mbar absolute.

Since the other trip alarm needs to trigger at zero gauge pressure rather than a fixed absolute pressure, we would suggest an additional gauge reference sensor to measure the suction pressure, and the DMP331 also has a 0 to -1000 mbar gauge to cover this over higher range up to atmospheric pressure.

To complete the set-up we would then suggest connecting each sensor to a separate display with a trip alarm such as the SRP94.

SRP94 Large LED Process Display Panel Mount Indicator

ATEX approval for Natural gas line

If I was to use this sensor in a hazardous (explosive) environment such as on a Natural gas line within a commercial building, would it need to be intrinsically safe (ATEX approved)?

ATEX is only applicable if the whole installation is to be ATEX class approved, typically this is only required if their is a potential danger of a flammable gas atmosphere such as petrochemical plant or an automotive paint shop. Our experience is that boiler rooms in commercial building do not require ATEX approved installations.

This HSE page states that “…Low pressure pipelines carrying mains gas to gas burning equipment have not traditionally been considered as sources of hazardous leaks, and area classification has not been applied in such circumstances….”.

If it is decided that you must use ATEX approved intrinsically safe sensor it will only be ATEX compliant if installed to ATEX standards and with other compatible intrinsically safe equipment such as zone barriers and suitable wiring between the hazardous area and the safe area where the control instrumentation normally resides.

Smaller size flush diaphragm

Is the flush diaphragm option for the DMP331 precision pressure transmitter only available in 1/2 BSP? Is there a limitation on accuracy with different flush diaphragm connection size, e.g. 1/4 BSP compared to 1/2 BSP?

The minimum flush diaphragm size is G1/2 (1/2 BSP) male for the DMP331, any smaller than this and the sensitivity and performance of the device will be affected. This is because as the isolation diaphragm gets smaller it becomes stiffer and much less flexible to changes in pressure.  The purpose of the isolation diaphragm is to protect internal sensor components and provide one basic material to the process media and therefore it has to be as thin as possible to allow the pressure to be transferred without any losses. To counteract the performance losses associated with a smaller isolation diaphragm, the isolation diaphragm must be made from a thinner material. However there is a limit to how thin the material can be before manufacturing the sensor becomes impractical or the isolation diaphragm becomes too vulnerable to mechanical damage.

Low range high accuracy natural gas pressure

I am looking at pricing and lead time for a pressure transmitter to measure natural gas pressure at an extremely low range of 0 – 100 mbarg, with 4-20mA output signal, 2-wire (loop powered) signal wiring connections and ¼” NPT pressure connection?

We would suggest the following DMP331 specification:

  • SKU ID: s1-dmp331-0001
  • Part No: DMP331-110-1000-1-1-TA0-N40-1-000
  • Pressure Range: 0 to 100
  • Units: mbar
  • Range Type: Positive Gauge (atm to +P)
  • Output Signal: 4-20mA (2 wire)
  • Accuracy: 0.1% FS (200ms response, 14bit res)
  • Electrical Connection: IP67 seal with 2m of cable
  • Process Connection: 1/4 NPT male
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM

3 wire 0-20mA output with 6 bar range

Please could you provide the part number & specification for a transmitter with a range of 0-6 barg, output of 0-20mA 3 wire, 1/4″ BSP male connection, and DIN 43650 plug & socket elec. conn.?

The DMP 331 part number & specification to meet all your requirements is as follows:

  • SKU ID: s1-dmp331-0010
  • Part No: 110-6001-2-3-100-300-1-000
  • Pressure Range: 6
  • Units: bar
  • Range Type: Positive Gauge (atm to +P)
  • Output Signal: 0-20mA (3 wire)
  • Accuracy: 0.35%FS >= 0.4 bar, 0.5% < 0.4bar (11-12bit resolution)
  • Electrical Connection: DIN43650A plug IP65
  • Process Connection: G1/4 DIN3852 male
  • Process Connector Material: Stainless steel 316L
  • Diaphragm Material: Stainless steel 316L
  • Media Exposed Seals: FKM

Related Documents

Specification data sheet


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