The SEMTECH Light Duty Vehicle (LDV) based Portable Emissions Measurement System (PEMS) is comprised of a Gas Analysis System (GAS) module, the Sample Control System (SCS) and the 4th generation Electronic Flow Meter (EFM4) all fully integrated, eliminating the need for interconnecting power and communication cables, pneumatic and heated lines.

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SEMTECH LDV: Portable Emissions Measurement System for Light Duty Vehicles

The SEMTECH LDV is comprised of three main modules, SEMTECH GAS, SEMTECH SCS, and EFM4. SEMTECH GAS houses the analytical devices for the gaseous measurements of CO, CO2, NO, and NO2. All electronics, including a web-based server, together with the sample handling elements and power distribution are accommodated in the SCS, which also serves as the platform for expanding the system to include other measurement capability, e.g. total hydrocarbon and methane measurements. The final piece to the system is the EFM4 which employs the traditional averaging pitot measurement technique used in previous generations of SEMTECH flow measurement devices, the EFM-HS and HTF. All key functional subsystems may be fully integrated, eliminating the need for troublesome communication and power cable connections, heated and pneumatic lines.

  • Features
  • Specifications
  • Options
  • Regulatory compliance and reporting
    • RDE-LDV, EC 427-2016 and EC 646-2016 amending EC 692-2008
    • US EPA 40CFR Part 1065
    • Automated post processing and reporting
  • Reduced energy consumption
  • Reduced size and weight
  • Improved aerodynamics
  • New safety features, such as in-cab emergency stop
  • Automated warm-up, zero, span, and calibration
  • Managed multi-user browser-based, real-time remote access capability
  • ICM - The In-vehicle Control Module doubles as a driver aid and in-vehicle communication platform.

Parameter CO CO2 NO NO2
Maximum Range 8% vol. 18% vol. 0 to 3000 ppm 0 to 1000 ppm
Resolution 10 ppm <0.01% vol. 0.1 ppm 0.1 ppm
Zero Drift (4 hour) ≤ ± 50 ppm ≤ ± 0.1% vol. ≤ 5 ppm
with Δt ≤ 10°C and using purified N as zero gas
Span Drift (4 hour) ≤ 2% of span value or
≤ ± 50 ppm, whichever is greater
≤ 2% of span value or
≤ 0.1% vol, whichever is greater
≤ 2% of reading or ≤ 5 ppm,
whichever is greater
with Δt ≤ 10°C and using purified N as zero gas
Linearity |xmin (a1 - 1) + a0| ≤ 0.5% of max
Slope a1 between 0.99 and 1.01
Standard Error of Estimates (SEE) ≤ 1% of max
Coefficient of Determination r2 ≥ 0.998
Accuracy < ± 2% of reading or
≤ ± 0.3% of full scale, whichever is greater
Precision ≤ 1% of span
Repeatability ≤ ± 2% of point or
≤ ± 1% of span, whichever is greater
Noise ≤ 2% of span
Sample Flow Rate 3 l/min nominal
Rise Time T10-90 ≤ 3 seconds
System Response Time T10-90 ≤ 12 sec
Data Rate 5 Hz


Parameter EFM4 Module SCS Module Gas Module CAB Module Fairing
Voltage 12 VDC from SCS 12 VDC 12 VDC from SCS P.o.E. n/a
Power Consumption 25W Typical
(Max. 50W)
60W Typical
(Max. 150W)
50W Typical
(Max 150W)
5W Typical
(Max. 45W)
Communications TCP/IP over Ethernet n/a
Storage Temperature -10°C to +60°C (dry)
Ambient Operating
-10°C to +45°C (0 - 100% RH non-condensing)
(W x D x H)
365x105x90 mm
14.3x4.1x3.4 in
435x410x105 mm
17.0x16.0x4.0 in
437x312x135 mm
17.0x12.0x5.0 in
115x205x45 mm
4.5x8.0x1.8 in

560x470x180 mm
22.0x18.5x7.0 in

Weight 3.7 -3.9 kg
8.2 - 8.6 lbs
(varies with tube size)
10.9 kg
24.0 lbs
8.9 kg
19.6 lbs
0.3 kg
0.75 lbs
2.7 kg
5.9 lbs
Electromagnetic Interference
& Susceptibility
CE Standards; IEC 61326:2002-2
  • EFM4- 4th generation SEMTECH Electronic Flow Meter for measurement of total raw exhaust mass flow.
  • FID- The SEMTECH LDV Flame Ionization Detector was designed to measure THC, both on-board and in the test cell.
  • Dual FID- The SEMTECH Dual Flame Ionization Detector is a simultaneous total hydrocarbon and methane real-time analyzer.
  • CPN- The SEMTECH Continuous Particulate Number is a continuous particle measurement device which measures the total number of particles present in an aerosol sample.
  • GPS - The GPS/Weather Probe uses a GPS receiver to track the route taken by the vehicle.
  • CAL - The Calibration module is a seven-to-one gas bottle changer with support for automatic gas divider control.
  • I/O - The SEMECH Input/Output (I/O) module supports a wide variety of analog inputs. This device allows you to add voltage, current and/or temperature sensors to your measurement data file. Inputs are time aligned to other signals including exhaust flow rate and gaseous concentrations.