
6500 VOCs analyzer is the analysis unit of VsCMS 6500 VOCs continuous monitoring system. It adopts the unique design of Deans Switch + double column separation + single FID to realize C2~C12 hydrocarbons monitoring with one instrument.
Nutech VsCMS 6500 VOCs Continuous Monitoring System – 57 PMAS Compounds Monitoring
For VOCs species analysis, Nutech provides continuous monitoring solutions based on different technologies (GC-FID, GC-FID/MS). The difference is that the analysis unit uses different analyzers. But because VOCs exist in ambient air at very low concentration (ppb or even ppt level), all these solutions need our innovative LTP technology to realize pretreatments like impurities removal and sample enrichment.
VsCMS 6500 is mainly used for the continuous monitoring of PAMS compounds in ambient air, which consists of sampling unit, analysis unit (including pretreatment), data collection and transmission unit, quality control unit, gas source unit and other auxiliary equipment.
Technical Data
Detection Method: LTP+GC-FID
Detection Limit: <0.1ppb
Precision: RSD<5%
Zero Noise: ≤0.05nmol/mol
Sampling Flow Rate: 5-120ml/min (Customizable)
System Residue: ≤0.1nmol/mol (90% Species)
Data Interface: 4~20mA,0~5V DC,RS232, ethernet port
Adsorption/Desorption Temperature: -10℃~350℃ (Adjustable)
Accuracy: ±10%
Maximum Temperature Rise Rate: 100℃/Sec
Temperature Control Precision: ±2℃
Working Gases:99.999% N2 (carrier gas, makeup), 99.999% air (combustion gas), 99.999% H2 (fuel gas)
Working Conditions: Temperature 10°C~40°C; RH: 20%~90%
Voltage: 110V/60Hz or 220V/50Hz±10%
Features
1. The innovative design of “doble column separation + Dean Switch + single FID” realizes full PMAS compounds analysis, and can report NMHC/TVOC concentration at the same time. A single instrument can meet the needs of high (C6 -C12) and low (C2 -C5 ) hydrocarbon monitoring, significantly reducing the cost of customers compared to the “high-carbon analyzer + low-carbon analyzer” solution.
2. The unique low temperature (-30°C) preconcentration technology effectively concentrates the target compounds to be measured and realizes rapid thermal desorption, which greatly improves the lower detection limit and meet the detection requirements of VOC species in low or ultra-low concentration air.
3. Cryogenic water treatment technology effectively removes water and CO2 from the sample air, which greatly improves the peak shape, extends the column life and avoids FID flameout.
4. With an FID detector, the instrument achieves good responses and a wide linear range.
5. The FID detector has real-time self-check function, can judge the working status, and can automatically ignite after flameout.
6. High precision MFC controls the sample gas and EPC controls the working gases like nitrogen, hydrogen and zero air. Precise control of the flow rate to ensure the accuracy of test results.
7. It has a reference analysis method (editable), and supports two quality control modes: quality control by online dynamic standard gas dilution and quality control by standard gas in SUMMA canister.
8. PC control, real-time data acquisition and transmission, automatic recording, storage, and support of QA/QC reports. With historical data (including atlas) query function, the system can automatically save and restore data if the power is cut off unexpectedly.
Chromatogram

Recommended Configuration for Complete Monitoring System
Besides the analysis unit (6500 VOCs analyzer), Nutech can offer the whole VOCs continuous monitoring system including the sampling unit, the analysis unit, the data collection and transmission unit, quality control unit, gas source unit and other auxiliary products.
Item | Model | Note |
Sampling Unit | ||
Sampling Tube (with heat tracing) | NST100 | Standard and Customizable |
Analysis Unit | ||
VOCs Online Analyzer | 6500 | Standard, LTP+GC-FID, PAMS. |
Data Collection & Transmission Unit | ||
Computer/IPC | IPC-610 | Standard. |
Data Collection Unit | N6500 V1.0 | Standard. |
Quality Control Unit | ||
Precision Dynamic Dilutor | 2202B | Standard. Can be purchased locally. |
Standard Gas – Internal Standard 4 Species | NSG-IS | Standard. Linde. |
Standard Gas – PAMS 57 | NSG-PAMS | Standard. Linde. |
Gas Source Unit | ||
High Purity Hydrogen Generator | NHG300 | Standard. |
Zero Air Generator | NAG1000 | Standard. |
High Purity Nitrogen | NG-N2 | Standard. Purchased locally. |
Other Auxilliary Equipment | ||
Meteorological Sensor | NTPL100 | Optional. |
Cabinet | N6837 | Optional. Customizable. |

This table is the list of standard configuration of VsCMS 6500 VOCs species continuous monitoring system recommended by Nutech, which can be customized according to customer’s requirements.
Project Reference

PAMS Compounds List
Acetylene | o-Ethyltoluene | n-Octane |
Benzene | m-Ethyltoluene | n-Pentane |
n-Butane | p-Ethyltoluene | 1-Pentene |
1-Butene | n-Heptane | cis-2-Pentene |
cis-2-Butene | n-Hexane | trans-2-Pentene |
trans-2-Butene | 1-Hexene | Propane |
Cyclohexane | Isobutane | n-Propylbenzene |
Cyclopentane | Isopentane | Propylene |
n-Decane | Isoprene | Styrene |
m-Diethylbenzene | Isopropylbenzene | Toluene |
p-Diethylbenzene | Methylcyclohexane | 1,2,3-Trimethylbenzene |
2,2-Dimethylbutane | Methylcyclopentane | 1,2,4-Trimethylbenzene |
2,3-Dimethylbutane | 2-Methylheptane | 1,3,5-Trimethylbenzene |
2,3-Dimethylpentane | 3-Methylheptane | 2,2,4-Trimethylpentane |
2,4-Dimethylpentane | 2-Methylhexane | 2,3,4-Trimethylpentane |
n-Dodecane | 3-Methylhexane | n-Undecane |
Ethane | 2-Methylpentane | o-Xylene |
Ethylbenzene | 3-Methylpentane | m-Xylene |
Ethylene | n-Nonane | p-Xylene |
PAMS Compounds Monitoring Introduction
Video Introduction by Southwest Ohio Air Quality Agency
Introduction by US EPA
The PAMS network is an ozone precursor monitoring network operated by state and local agencies. The PAMS program was originally started in the early 1990s to meet the requirements of the Clean Air Act (CAA). Significant revisions to the PAMS requirements were made as part of the 2015 Ozone National Ambient Air Quality Standard (NAAQS) review. The revised PAMS requirements call for ozone precursor measurements to be made at existing NCore sites (a multi-pollutant monitoring network) in Core Based Statistical Areas (CBSAs) with a population of one million or more . The main objective of the required PAMS sites is to develop a database of ozone precursors and meteorological measurements to support ozone model development and track the trends of important ozone precursor concentrations.
Below is the VOCs related monitoring requirements at each PAMS site:
- Hourly averaged speciated volatile organic compounds (VOCs)
- Three 8-hour averaged carbonyl samples per day on a 1 in 3 day schedule, or hourly averaged formaldehyde