eraspec is eralytics’ industry-proven multi-fuel analyzer with several thousand installations worldwide. It offers measurements of fuel component concentrations, complex properties like RON or cetane number, and density for gasoline, diesel fuel, jet fuel and even specialized fuels like ethanol fuels. A single push of a button delivers all results within 1 minute.
eraspec at a glance
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FTIR fuel analysis
In FTIR fuel analysis a spectrum of the analyzed fuel is recorded in the mid-infrared region using an Fourier transform spectrometer. Depending on the chosen method a single measurement is able to detect over 40 parameters within a few seconds. For gasoline measurements e.g. RON, MON, AKI, distillation properties, esters and aromatics concentrations are determined. When analyzing diesel aromatics, cetane improvers, biodiesel and many more can be quantified. Analyzing biodiesel eraspec distinguishes between FAME / FAEE and vegetable oil. It measures FAME in full compliance with ASTM D7806 and EN 14078. Typical parameters for jet fuel include FAME, aromatics, freezing and flash point, smoke point and distillation parameter, as well as viscosity.
Unique fourfold cell design
The measurement of different fuels implicates different requirements for the analyzer. eraspec was launched with the leading-edge triple cell design which is now the standard for all eraspec analyzers making future instrument upgrades extremely easy. This innovation uses a 20 μm cell to measure gasoline and a 100 μm cell to measure diesel and jet fuel. With the third cell eraspec automatically performs a reagent free reference measurement whenever needed. For special applications eraspec is also available with eralytics
unique fourfold cell design. Examples include high precision testing of FAME and cetane improvers as well as the up-grade of eraspec with the innovative NIR/PLS module. This module extends the spectral range to the NIR range (4000-4500 cm -1 ) by a
measurement through a fourth 500μm measuring cell. This allows for the exploitation of additional valuable information about the backbone of fuels leading to a factor of 2 better SEC for octane
numbers RON & MON.
NIR/PLS module
The NIR/PLS module extends the spectral range of eraspec to the NIR range (4000–4500 cm -1 ) by taking an additional measurement through a 500 μm measuring cell. In this range, so-called combination bands show absorption, enabling the distribution of alkanes to be determined. This significantly influences important fuel properties. Combining this NIR information with MIR data on aromatics, oxygenates and olefins within eralytics innovative PLS model improves the SEC for RON and MON by a factor of 2.
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Concentrations vs. parameters
eraspec can directly derive fuel component concentrations from the measured IR spectrum. That includes aromatics such as benzene (ASTM D6277), oxygenates such as MTBE or ethanol (ASTM D5845) and octane boosters such as MMT for the measurements of gasoline. Knowing the exact fuel composition, however, also allows to calculate more complex fuel parameters. eraspec uses chemometrical models, based on fuel libraries, to calculate parameters such as RON, MON or distillation and evaporation fractions from the spectrum for gasoline. It covers cetane number and index and many more for diesel fuel.
Expandable SGS® fuel library
Each eraspec comes with an international factory library using more than 1.000 fuel samples from 89 countries from the SGS® WORLDWIDE FUEL SURVEY. All fuel samples were analyzed at SGS® Germany based on primary measuring methods for fuel properties like Research Octane Number (RON) and Motor Octane Number (MON). Based on several thousand eraspec installations eralytics also offers customized libraries of international fuel calibration samples. New customer samples can easily be added to the library directly on the analyzer via its large touchscreen.
Integrated ASTM D4052 density measurement
eraspec is available with eralytics’ integrated state-of the-art temperature-controlled U-tube density meter modules DENS7777 and DENS4052. In combination with the ultra-light density meter module DENS4052 (patented), offering density measurements in full compliance with ASTM D4052 & ISO 12185 (r = 0.0001 g/cm3), eraspec can measure density, benzene and FAME in full compliance with international fuel specifications, like ASTM D4814, EN228 and EN590. In its standard version ERASPEC is now equipped with eralytics new DENS7777 U-tube density module that is also temperature-controlled and measures in full compliance with ASTM D7777 & ISO 15212 (r = 0.0005 g/cm3).
Unknown or contaminated samples
The “Automatic Fuel Recognition” (AFR) Module allows an easy measurement of unknown samples with the eraspec fuel analyzer. It recognizes if gasoline, diesel or jet fuel is measured and automatically starts the correct analysis according to the registered fuel type.
Most common contaminations of gasoline can be measured with the “Gasoline Contamination Module”. Typical substances that can be quantified are DMM, N-Methyl-Aniline, Diolefines, Aniline, DMC, various Butyl-Acetates and more.
This makes the eraspec fuel analyzer to a reliable tool to fight fuel adulteration fraud directly at the gas stations.
Patented design
The heart of the eraspec fuel analyzer is a patented corner-cube retro-reflector FTIR spectrometer. For highest precision it is laser and temperature controlled and its spectral resolution is tailored to the task of fuel analysis. This reduces any noise to an absolute minimum, increasing the repeatability and lowering the possible limits of detection.
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Option: 10-position autosampler for high sample throughput
eralytics’ 10-position autosampler is an optional accessory for the spectral fuel analyzer eraspec . The 10-position autosampler is directly attached to the instrument allowing it to conveniently connect up to 10 samples simultaneously. It is the perfect solution for higher sample throughput and even more efficiency. All instruments maintain their portability, even with the 10-position autosampler attached. Read more in the 10-position autosampler datasheet.
Measurement procedure
With eraspec a spectral analysis of fuels can be done in 3 simple steps:
- Enter sample ID and select the measurement standard and the library to be used for calculating properties
- Put your sample next to the fuel analyzer and insert the inlet tube
- Press the RUN button
The measurement steps are visualized on the display, showing the deflection of the moving mirror of the interferometer. When the measurement is completed the results are displayed and can be printed or added to a library with a single click. When adding the results of the fuel analyzer to a library an editor for entering known properties will appear. This will improve the quality of future measurements using the eraspec fuel analyzer, as the library can be tailored to a specific application.
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Module parameters
Gasoline
| Properties1 | Range |
|---|---|
| Research Octane Number (RON) | 70 – 110 |
| Motor Octane Number (MON) | 60 – 105 |
| Anti Knock Index (AKI) | 65 – 107 |
| RVP & DVPE | 35 – 105 kPa |
| Distillation fractions | IBP, T10, T50, T90, FBP |
| Evaporation fractions | E70, E100, E150, E180, E200, E300, E350, E370 |
| Density (built-in U-tube cell) | 0 – 3 gcm-3 |
| Driveability Index, VOC Emissions Calculator, Vapor Lock Index (VLI), User Definable Parameters | |
| Sum Parameters | Range |
|---|---|
| Aromatics1 | 0 – 80 Vol% |
| Olefins1 | 0 – 80 Vol% |
| Di-Olefins2 | 0 – 20 Vol% |
| Oxygenates2 | 0 – 80 Vol% |
| Oxygen2 | 0 – 12 wt% |
| Anilines2 | 0 – 25 Vol% |
| Esters2 | 0 – 30 Vol% |
| Saturates | 0 – 100 Vol% |
| Oxygenate Parameters2 | Range |
|---|---|
| MTBE | 0 – 20 Vol% |
| ETBE | 0 – 25 Vol% |
| TAME | 0 – 25 Vol% |
| TAEE | 0 – 20 Vol% |
| DIPE | 0 – 20 Vol% |
| Dimethoxymethane (DMM) | 0 – 20 Vol% |
| Methanol | 0 – 15 Vol% |
| Ethanol | 0 – 100 Vol% |
| Iso-Propanol | 0 – 20 Vol% |
| 1-Butanol | 0 – 100 Vol% |
| 2-Butanol | 0 – 25 Vol% |
| Isobutanol | 0 – 50 Vol% |
| tert-Butanol | 0 – 25 Vol% |
| Dimethylcarbonate (DMC) | 0 – 15 Vol% |
| Methylacetate | 0 – 15 Vol% |
| Ethylacetate | 0 – 15 Vol% |
| Isobutylacetate | 0 – 15 Vol% |
| Sec-Butylacetate | 0 – 15 Vol% |
| Nitromethane | 0 – 9 m% |
| Aromatics2 | Range |
|---|---|
| Benzene | 0 -10 Vol% |
| Toluene | 0 – 20 Vol% |
| o-Xylene | 0 – 20 Vol% |
| m-Xylene | 0 – 20 Vol% |
| p-Xylene | 0 – 20 Vol% |
| Ethylbenzene | 0 – 20 Vol% |
| Propylbenzene | 0 – 20 Vol% |
| 2-Ethyltoluene | 0 – 20 Vol% |
| 3-Ethyltoluene | 0 – 20 Vol% |
| 4-Ethyltoluene | 0 – 20 Vol% |
| Pseudocumene | 0 – 20 Vol% |
| Hemillitol | 0 – 20 Vol% |
| Mesitylene | 0 – 20 Vol% |
| Iso-Durene | 0 – 20 Vol% |
| Durene | 0 – 20 Vol% |
| Naphthalene | 0 – 10 Vol% |
| Octane Boosters2 | Range |
|---|---|
| MMT | 0 – 10000 mg/L |
| CMT | 0 – 10000 mg/L |
| Manganese (by MMT) | 0 – 2500 mg/L |
| DCPD (Dicyclopentadiene) | 0 – 15 Vol% |
| Anilines2 | Range |
|---|---|
| Aniline | 0 – 15 Vol% |
| N-Methylaniline | 0 – 15 Vol% |
| o-Methoxyaniline | 0 – 20 Vol% |
| o-Toluidine | 0 – 20 Vol% |
| m-Toluidine | 0 – 20 Vol% |
| p-Toluidine | 0 – 20 Vol% |
| N,N, Dimethylaniline | 0 – 20 Vol% |
Easy addition of unlimited user-defined properties.
1 … The range and repeatability for all correlated properties depend on the used database.
2 … Lowest concentrations correspond to the limit of detection (LOD).
Diesel
| Properties1 | Range |
|---|---|
| Cetane Number | 20 – 80 |
| Cetane Index | 20 – 80 |
| Distillation fractions | IBP, T10, T50, T65, T85, T90, T95, FBP |
| Evaporation fractions | E250, E350 |
| CFPP | -50 – +20 °C |
| Viscosity @ 40 °C | 0 – 10 mm2/s |
| Density (built-in U-tube cell) | 0 – 3 gcm-3 |
| Parameters | Range |
|---|---|
| Total Aromatics1 | 0 – 80 Vol% |
| Polynuclear Aromatics (PNA)1 | 0 – 80 Vol% |
| Benzene2 | 0 – 5 Vol% |
| Cetane Improver (2-EHN, IPN)2 | 0 – 20 000 mg/L |
| Dimethoxymethane (Methylal)2 | 0 – 20 Vol% |
| FAME2 | 0 – 100 Vol% |
| FAEE2 | 0 – 100 Vol% |
| Vegetable Oil2 | 0 – 65 Vol% |
| Distinction between FAME (Biodiesel) and vegetable oil | |
| Separate calibrations for different FAME / FAEE sources | |
Easy addition of unlimited user-defined properties.
1 … The range and repeatability for all correlated properties depend on the used database.
2 … Lowest concentrations correspond to the limit of detection (LOD).
Jet Fuel
| Properties1 | Range |
|---|---|
| Freezing Point | -80 – -20 °C |
| Flash Point | -20 – +100 °C |
| Smoke Point | 0 – 1000 mm |
| Viscosity at 20°C | 1.2 – 2.1 mPas |
| Viscosity at -20°C | 0 – 10 mPas |
| Distillation fractions | IBP, T10, T50, T65, T85, T90, T95, FBP |
| MSEP | 50 – 100 % |
| Density (built-in U-tube cell) | 0 – 3 gcm-3 |
| Parameters | Range |
|---|---|
| Total Aromatics1 | 0 – 80 Vol% |
| FAME concentration2 | 0 – 6 Vol% |
| Polynuclear Aromatics (PNA)1 | 0 – 10 Vol% |
Easy addition of unlimited user-defined properties.
1 … The range and repeatability for all correlated properties depend on the used database.
2 … Lowest concentrations correspond to the limit of detection (LOD).
Fuel Ethanol / Methanol
Fuel Ethanol
| Parameter2 | Range |
|---|---|
| Ethanol | 0 – 100 Vol% |
| Water | 0 – 2 Vol% |
| Methanol | 0 – 15 Vol% |
| Denaturant | 0 – 100 Vol% |
| Density (built-in U-tube cell) | 0 – 3 gcm-3 |
Fuel Methanol
| Parameter2 | Range |
|---|---|
| Methanol | 0 – 100 Vol% |
| Density (built-in U-tube cell) | 0 – 3 gcm-3 |
Easy addition of unlimited user-defined properties.
2 … Lowest concentrations correspond to the limit of detection (LOD).
eraspec feature video
- Characterization of over 40 fuel parameters within 60 seconds
- Patented rugged FTIR and laser / temperature design for highest precision
- Factory calibrated with a matrix of several hundred international fuels
- Easy expandable libraries to tailor the reference matrix to special applications
- Tailored path-lengths for various applications
- Built-in oscillation U-tube density meter (ISO 15212)
- Comprehensive fuel analysis of gasoline, diesel fuel and jet fuel in seconds
- Biodiesel (ASTM D7806) and vegetable oil detection in diesel fuel
eraspec operation video
Watch this video to get an overview of the standard operation of eraspec: From installation to measurement and some extended measuring options.
eraspec in detail
Technical Specifications for eraspec
- Available Test Methods
- ASTM D5845, ASTM D6277, D4052/D7777, ASTM D7806, E1655, EN 238, EN 14078, ISO 12185, ISO 15212, IP 559
- Correlation to…
- ASTM D56, D86, D323, D445, D613, D976, D1319, D1322, D1840, D2386, D2699, D2700, D3828, D4814, D4815, D5191, D5769, D6371, D6379, D6378, D7153, D7371; EN 116, EN 13016; ISO 3104, ISO 3405, ISO 5163, ISO 5164, ISO 5165
- Spectrometer Type
- Patented mid-FTIR spectrometer
Laser and temperature controlled design - Measurement Cell
- 20 µm and / or 100 µm path length cell, reference cell
Optimized dual or triple position cell design for gasoline, diesel, and jet fuel measurements
Optional fourfold-cell for special applications (e.g. 400 µm) - Calibration
- Factory calibrated with a matrix of several hundred international fuels
- Spectral Libraries
- Easy addition, expansion and exchange of individual fuel libraries
On the fly recalculation of libraries without delaying any measurements - Density Meter
- Temp. controlled oscillating U-tube density meter (0-3 g/cm3):
Standard density module (r = 0.0005 g/cm3; ASTM D7777)
High precision density module (r = 0.0001 g/cm3; ASTM D4052) - Available Analyzer Modules
- – Gasoline module (ASTM D5845, ASTM D6277, and several correlation methods)
– MMT / CMT module (determination of MMT, CMT and Manganese)
– Contamination gasoline module
– Benzene (determination according to EN 238)
– Synthetic fuel module (for gasoline)
– Diesel module (with several preprogrammed correlation methods)
– 2EHN Cetan improver module
– Low FAME module (for determination of FAME in diesel or jet fuel)
– EU FAME module (for determination of FAME according to EN 14078)
– Ethanol fuel module (ASTM D4806)
– Methanol fuel module
– Automatic fuel recognition module
– Jet fuel module (with several preprogrammed correlation methods) - Measurement Time
- 60 seconds, includes fully automated rinsing, filling and measurement (DENS7777)
Warm-up time 30 second - Sample Introduction
- Directly from the sample container by an integrated pump
- Sample Volume
- 10 mL
- Cleaning
- Automatic rinsing with next sample or solvent
Flow cell protected by an inegrated filter - Display of Fuel Spectra
- Direct comparison of spectra on the color touchscreen
Overlay of fuel spectra with spectra of pure substances - Display
- Industry proven 8.4″ multilingual color touchscreen
- Languages
- English, German, French, Spanish, Russian, Chinese
Additional langages available upon request - Interfaces
- Built-in PC with Ethernet, 5 x USB-A, 1xUSB-B and RS232 interfaces
Direct LIMS connectivity via LAN and output to printer or PC
Optional input by keyboard, mouse and barcode scanner
Wifi via external USB dongle - Remote Control
- Remote service capability via Ethernet interface
- PC Software
- erasoft RCS – remote control Windows® software for multi-instrument remote control, convenient data transfer, viewing spectra and result analysis
- Result Satabase
- 50 000+ detailed test reports and spectra storable in internal memory
- Alarm Tracking
- All alarm messages are stored the the database together with the results
- Autosampler
- Optional 10-position auto-sampler – directly attached
- Operating Conditions
- Temperature range 5 °C to 45 °C
Humidity up to 90% RH, non-condensing - Power Requirements
- Auto-switching 85-264 V AC, 47-63 Hz, max. 150 W
Field application: 12 V DC vehicle battery, adapter available - Dimensions & Weight
- (W x D x H) = 29.1 x 32.9 x 34.8 cm (11.5 x 12.9 x 13.7 in) / 11.3 kg (24.9 lb)
Downloads for eraspec
- eraspec Brochure English
- eraspec Brochure German
- eraspec Brochure Spanish
- eraspec Brochure French
- eraspec Brochure Portuguese
- eraspec Brochure Chinese
- Datasheet: 10-Position Autosampler English
- Application Note: Rapid Determination of FAME using ATM D7806
- Application Note: HVO100 identification on-site with FTIR spectroscopy
- Article on “On-site Fuel and Lubricant Quality Control by portable FTIR analysers”
- Article On “Enhancing property predictions of gasoline using MIR and NIR-FTIR spectroscopy” | Petro Industry News 09/2025
Frequently Asked Questions about eraspec
eraspec determines octane numbers by correlating the measured sample spectrum against a comprehensive reference database of gasoline spectra with known octane values. Pre-installed with a global fuel reference library, eraspec delivers highly accurate octane number predictions for unknown samples. While the base instrument operates in the mid-infrared region, an optional configuration integrates mid- and near-IR (MIR+NIR) spectroscopy for enhanced precision. Users can easily calibrate either module with local data to optimize instrument accuracy through a brief, straightforward training process. Get more on MIR + NIR FTIR Spectroscopy in the application note Enhancing Property Predictions of gasolineusing MIR + NIR FTIR Spectroscopy
Octane prediction accuracy can be enhanced by training eraspec with local fuel data. For maximum precision, an optional configuration integrates eralytics’ unique dual-spectrum combination of mid- and near-IR spectroscopy. When using the standard “Gasoline” module, measurement precision can be optimized by training the instrument with localized fuel data – a workflow highly effective for quality control at refineries and distribution terminals. Alternatively, the optional “Gasoline MIR+NIR” module integrates mid- and near-infrared spectroscopy. This configuration utilizes multiple pathlength measurement cells to maximize the signal-to-noise ratio, followed by advanced chemometric calculations, which shows it full strength if significantly different samples are measured from unknown sources. Get more on MIR + NIR FTIR Spectroscopy in the application note Enhancing Property Predictions of gasolineusing MIR + NIR FTIR Spectroscopy
eraspec itself requires no sample preparation for standard fuel samples, allowing direct introduction of typical samples into the analyzer without prior conditioning. For routine analysis though introducing samples at ambient temperature is recommended. While certain standard test methods like EN 238, EN 14078 or GB/T 23801 mandate sample dilution for compliance, eraspec can report these parameters without pre-dilution using different methods. If you need further information please contact our service and support team
eraspec quantifies FAME in diesel in full compliance with ASTM D7806 and EN 14078. The analyzer can also distinguish petroleum-based diesel from HVO100 (hydrotreated vegetable oil). For ASTM D7806 testing, optional configurations are available to lower the limit of detection. During analysis, the instrument’s advanced software also screens for potential contamination products or spectral interferents that look similar to FAME, automatically alerting the operator if anomalies are detected. If you need further information please contact our service and support team
eraspec features an integrated, temperature-controlled density meter available in two variants, delivering full compliance with or exceeding either ASTM D4052 or ASTM D7777 standard test methods. During analysis, eraspec simultaneously fills the IR cell and the density meter with the sample. Concurrent testing delivers an ASTM D7777-compliant density result alongside the IR spectrum. If the high-precision option is installed, a fully compliant ASTM D4052 measurement, including an automated bubble detection check, is performed immediately afterward. Get more on this on the eraspec product site