Semtech Efm Hs High Speed Flow Tube

SEMTECH® EFM-HSHigh Speed Exhaust Flow Meter

Sensors’ High Speed Exhaust Flow Meter, the SEMTECH EFM-HS, adds exciti ng capabiliti es and features to the product line. With a sampling rate of up to 2500 Hz and four, dual stage diff erenti al pressure transducers, the EFM-HS accurately measures every forward and reverse fl ow pulsati on from idle to maximum fl ow rate, and properly accounts for these pulsati ons in the exhaust fl ow determinati on. This is a tremendous advantage over low speed exhaust fl owmeters which are suscepti ble to measurement error from high frequency pulsati ons. The EFM-HS also off ers a long list of other performance enhancements and convenience features that set it apart from the competi ti on.

Mass fl ow rate accuracy and linearity of the SEMTECH EFM-HS exceeds the US and European performance standards over a 50:1 turndown rati o. The EFM-HS can be used to measure exhaust fl ow rate from both spark and compression igniti on engines, as a stand-alone device, or in conjuncti on with the emissions measurements of the SEMTECH-DS or other gas analyzers, to compute real-ti me mass emissions.

Emissions Measurement

Solutions

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SEMTECH EFM-HSHigh Speed Exhaust Flow Meter

Opti onal Confi gurati ons

High Speed Data Acquisiti on: Data output rate of 500 Hz is available.

Stand-Alone Confi gurati on: SENSOR Tech-EFMHS applicati on enables system operati on from a Windows environment.

Dual Channel Confi gurati on: A second channel with a full set of transducers can be added to the system in the same electronics module. This is useful for measuring a dual exhaust system, exhaust and EGR simultaneous measurement, or detecti ng undeveloped fl ow conditi ons.

Customized Interface: Sensors can develop a customized device driver to interface with various host systems.

System Features and Benefi ts

High Speed Sampling: The EFM-HS internally samples the diff erenti al pressure channels at up to 2500 Hz, accounti ng for every pressure pulse from an engine, from idle to maximum rpm. Standard output rate is 5 Hz.

Embedded Calibrati on: Calibrati on coeffi cients embedded in the fl ow tube electronics are automati cally recognized on connecti on, enabling multi ple tubes to be used with one control module.

Multi ple Tube Sizes: Eight fl ow tube sizes accommodate engines from less than 0.8L displacement up to 24L.

Back Purge: A soft ware controlled back purge pump is included in the fl ow tube assembly along with solenoids that route high pressure air backward through the pitot tube, purging contaminants and any condensati on in the pressure lines. No dismantling is required.

Auto Zero: With a single soft ware command, internal solenoids open the pressure sensors to ambient air, allowing fast and easy zeroing while the engine is sti ll operati ng.

Weatherproof Constructi on: The unit can be used off -road and in other harsh environments. All components are weatherproof to IP54 (NEMA 3) standards.

Heated Components: The averaging pitot tube and pressure lines are heated at the fl ow tube assembly in order to prevent condensati on and freezing in cold weather. The diff erenti al pressure sensors are housed in a temperature controlled manifold in the control module for added stability.

Sample Screen from SENSOR Tech-EFMHS

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SEMTECH EFM-HSHigh Speed Exhaust Flow Meter

The Technology

Operati ng under the Bernoulli principle, the SEMTECH EFM-HS uses four high performance, dual-stage, diff erenti al pressure transducers, sampling conti nuously at up to 2500 Hz, measuring every pressure pulse from an engine. The sensors are housed in a heated manifold, eliminati ng thermal drift . The eight combined diff erenti al pressure ranges span nearly fi ve orders of magnitude, allowing accurate measurements over a wide range of fl ow rates. The smallest transducer range is 0.025 kPa with a resoluti on of 5x10-5 kPa, while the highest range is 16.5 kPa.

A proprietary algorithm computes a spline fi t of the eight high speed diff erenti al pressure signals, and calculates a running square-root average that is used to determine output fl ow rates at 5 Hz (500 Hz with the high speed opti on). The high speed sampling and symmetrical design of the averaging pitot tube provides the EFM-HS with the ability to accurately measure reverse fl ow due to engine pulsati ons, and to properly account for this phenomenon in the average fl ow rate determinati on.

Sensors, Inc. • 6812 State Rd. • Saline, Michigan 48176 • PH:(734) 429-2100 • FX:(734) 429-4080 • www.sensors-inc.comSensors Europe GmbH • Feldheider Str. 60 • 40699 Erkrath • Germany • PH: +49 (0) 2104-14188-0 • FX: +49 (0) 2104-14188-14

SEMTECH EFM-HS Available Sizes and Flow RatesRecommended Application: Engine Size (L) & Type

GasDiesel

< 1 †

< 0.8< 2 †

< 1.5< 2

< 1.52 - 5

1.5 - 4> 5

4 - 6-

6 - 12-

12 - 18-

> 18

Flow Tube Outer Diameter

inmm

1 25

1.538

251

2.564

376

4102

5127

6152

Flow Tube Length (Length including extension)

inmm

20 (26)508 (660)

20 (26)508 (660)

20 (26)508 (660)

25 (32.5)635 (825)

25 (34)635 (864)

25 (37)635 (940)

30 (45)762 (1143)

36 (54)914 (1372)

Backpressure Flow rate at 200°C, SCFM (m3/min)

10” H202.5 kPa

67(1.9)

109(3.1)

175 (4.9)

425(12.0)

600(17.0)

1100(31.2)

1700(48.1)

2380(67.3)

15” H203.75 kPa

83(2.4)

146(4.1)

215(6.1)

550(15.6)

775(22.0)

1350(38.2)

2100(59.5)

2940(83.3)

Backpressure Flow rate at 400°C, SCFM (m3/min)

10” H2O 2.5 kPa

56 (1.6)

91(2.6)

147(4.2)

356(10.0)

503(14.3)

922(26.2)

1425(40.3)

1995(56.4)

15” H2O3.75 kPa

69.6(2.0)

122(3.5)

180(5.1)

461(13.1)

649(18.4)

1132(32.0)

1760(49.9)

2465(69.8)

† Non-Turbo

NOTE: Specifications are subject to change without no-tice. While due caution has been exercised in the produc-tion of this document, possible errors and omissions can occur.

R 05/10

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SEMTECH EFM-HSHigh Speed Exhaust Flow Meter

Exhaust temperature range: -5 to 700°C standard construction (higher temperature capability available upon request)

Exhaust temperature accuracy: ± 1% of reading or ± 2°C, whichever is greater

Flow measurement linearity: < 1.0% of full scale

Exceeds 1065 Subpart D and ISO 16183 standards

Flow measurement accuracy: ± 2% of reading or ± 0.5% of full scale, whichever is greater

Warm up time: < 5 minutes at 20°C ambient

System response time: < 2 ms

Data rate: 5 Hz standard

High Speed option data rate: 500 Hz (100 Hz display rate)

Resolution: 0.1 SCFM

Power requirements: 12VDC , 30W; 110VAC

Communications: RS 232

Control module dimensions: 36cm x 18cm x 10cm (LxDxW)

Control module weight: 4kg (9 lbs)

Length*

Diameter*

69.0mm

381.0mm

49.0mm*see chart above. NOTE: Accurate measurments require adequate straight pipe length prior to the exhaust entering the measuring pitot. This is ensured with our tube extension kits, refer-enced in the length specifications in the chart above.