**Executive Summary**
This document lists OCEMS models with NPL verification certificates or provisional letters of confirmation. The list is updated periodically, with data current as of December 27, 2025. The document includes the certificate holder, certificate type, model number, gases/dust covered, and certificate number. The document also provides contact details for the certificate holders.
**Key Points / Main Content**
* **OCEMS Models Listed:** The document provides a list of OCEMS models.
* **Certificate Types:** The models are listed with either NPL Verification Certificates or Provisional Letters of Confirmation.
* **List Updates:** The list is updated periodically:
* List as on 21.11.2025
* List updated on 01.12.2025
* List updated on 10.12.2025
* List updated on 12.12.2025
* List updated on 27.12.2025
* **Certificate Information:** For each model, the following information is provided:
* Certificate Holder
* Certificate Type
* Model Number
* Gases/Dust detected
* Certificate Number
* **Enforcement Notes:**
* For NPLI CS/CEMS/VC-2025-01S, the verification certificate no. NPLI CS/CEMS/VC-2025-01S is enforced in place of the verification certificate no. NPLI CS/CEMS/VC-2025-01.
* For NPLI CS/CEMS/VC-2025-02S, the verification certificate no. NPLI CS/CEMS/VC-2025-02S is enforced in place of the verification certificate no. NPLI CS/CEMS/VC-2025-02.
* For NPLI CS/PM-CEMS/VC-2025-03A, the verification certificate no. NPLI CS/PM-CEMS/VC-2025-03A is enforced in place of the verification certificate no. NPLI CS/PM-CEMS/VC-2025-03.
* For NPLI CS/CEMS/VC-2025-04S, the verification certificate no. NPLI CS/CEMS/VC-2025-04S is enforced in place of the verification certificate no. NPLI CS/CEMS/VC-2025-04.
* For NPLI CS/CEMS/VC-2025-36, a revised copy of the certificate is enforced.
* **Contact Details:** The document provides contact details (email and phone number) for each certificate holder.
**Impact Analysis**
**Certificate Holders**
**Impact**
* Affected by the list of OCEMS models issued with NPL verification certificates or provisional letters of confirmation.
* Need to ensure compliance with the latest verification certificates or provisional letters of confirmation.
* Need to maintain up-to-date contact information.
**Action Required**
* Review the listed OCEMS models and verify that their equipment is covered by a valid verification certificate or provisional letter of confirmation.
* Update contact information if it has changed.
Key Entities Referenced
NPLI CS/CEMS/VC : Certificate number prefix indicating a certificate related to Continuous Emission Monitoring Systems verified by NPLI (National Physical Laboratory of India)
NPLI CS/PM-CEMS/VC : Certificate number prefix indicating a certificate related to Particulate Matter Continuous Emission Monitoring Systems verified by NPLI (National Physical Laboratory of India)
NPLI : National Physical Laboratory of India, responsible for verifying and issuing certificates related to emission monitoring systems.
OCEMS : Online Continuous Emission Monitoring Systems. This list pertains to these systems and their verification status.
Verification Certificate : A type of certificate issued for OCEMS models, indicating verification of their performance and compliance.
See Full Document Text
List of OCEMS models issued with NPL verification certificate/provisional letter of confirmation as on 21.11.2025
Sr. No. Certificate Holder Certificate Type Model No. Gases/Dust Certificate
SO2
1 PRIMA Equipment Verification Certificate PSGM-1-D-AGS NO NPLI CS/ CEMS/ VC-2025-11
SO2
NO2
NH3
NO
Formaldehyde
Phenol
2 NEVCO Engineers Pvt Ltd. Verification Certificate AR602Z H2O NPLI CS/ CEMS/ VC-2025-01S *1
(UV)/NHg/N *1 Hg*1
CO
HCl
NEVCO Engineers Pvt Ltd. HF
3 Verification Certificate AR650/N *2 H2O NPLI CS/ CEMS/ VC-2025-02S *2
CO2*2
CH4*2
4 Sintrol Oy Verification Certificate S305QAL PM NPLI CS/ PM-CEMS/VC-2025-03A *3
5 NEVCO Engineers Pvt. Ltd. Verification Certificate O2000 O2 NPLI CS/ CEMS/ VC-2025-04S *4
SO2
NO
ACE GASANALYSERS
CO
PRIVATELIMITED
6 Provisional Letter of Confirmation ACE10000XXHE CO2 NPLI CS/ CEMS/ PLoC-2025-16
SO2
NO
7 Endress+Hauser India Verification Certificate S700 CO NPLI CS/ CEMS/ VC-2025-08
8 Endress+Hauser India Verification Certificate FWE200DH PM NPLI CS/ PM-CEMS/VC-2025-09
Endress+Hauser (India) Pvt.
9 Ltd. Verification Certificate SB 100 PM NPLI CS/ PM-CEMS/VC-2025-05
Endress+Hauser (India) Pvt.
10 Ltd. Verification Certificate SP 100 PM NPLI CS/ PM-CEMS/VC-2025-07
Endress+Hauser (India) Pvt.
11 Ltd. Verification Certificate SP30 PM NPLI CS/ PM-CEMS/VC-2025-06
Endress+Hauser (India) Pvt.
12 Ltd. Verification Certificate SB30 PM NPLI CS/ PM-CEMS/VC-2025-10
13 Envea India Private Limited Verification Certificate PCME QAL 181 PM NPLI CS/ PM-CEMS/VC-2025-12
14 Envea India Private Limited Verification Certificate DM 170 PM NPLI CS/ PM-CEMS/VC-2025-13
CO
NOx
SO
2
CO
2
15 Horiba India Pvt. Ltd. Verification Certificate ENDA 5000 Series O 2 NPLI CS/ CEMS/VC-2025-21
SO
2
NO
CO
Envirozone Pvt. Ltd. O2 para
(Envirozone Instruments & CO
2
16 Equipments Pvt. Ltd.) Verification Certificate ZPA-CEMS O2 (ZrO2) NPLI CS/ CEMS/VC-2025-22
SO
2
NO
Envirozone Pvt. Ltd. CO
(Envirozone Instruments & O2 (Pa)
17 Equipments Pvt. Ltd.) Verification Certificate ZRE - ZRE/ZFK 7 O2 (Zi) NPLI CS/ CEMS/VC-2025-23
DURAG India
18 Instrumentation Pvt. Ltd. Verification Certificate D-R-290 PM NPLI CS/ PM-CEMS/VC-2025-24
DURAG India
19 Instrumentation Pvt. Ltd. Verification Certificate D-R-320 PM NPLI CS/ PM-CEMS/VC-2025-25
DURAG India
20 Instrumentation Pvt. Ltd. Verification Certificate HM 1400 TRX Hg NPLI CS/CEMS/VC-2025-26Envirozone Pvt. Ltd.
(Envirozone Instruments &
21 Equipments Pvt. Ltd.) Provisional Letter of confirmation EZ 320-PMLS PM NPLI CS/PM_CEMS/PLoC-2025-28
Important Note:
*1 Henceforth, the verification certificate no. NPLI CS/CEMS/VC-2025-01S is enforced in place of the verification certificate no. NPLI CS/CEMS/VC-2025-01
*2 Henceforth, the verification certificate no. NPLI CS/CEMS/VC-2025-02S is enforced in place of the verification certificate no. NPLI CS/CEMS/VC-2025-02
*3 Henceforth, the verification certificate no. NPLI CS/PM-CEMS/VC-2025-03A is enforced in place of the verification certificate no. NPLI CS/PM-CEMS/VC-2025-03
*4 Henceforth, the verification certificate no. NPLI CS/CEMS/VC-2025-04S is enforced in place of the verification certificate no. NPLI CS/CEMS/VC-2025-04Sr. No. Cirtificate Holder Certificate Type Model No. Gases/Dust Certificate Number
List Updated on 01.12.2025
22 Envea India Private Limited Verification Certificate DM 210 PM NPLI CS/ PM-CEMS/VC-2025-14
MIR9000e CO
NOx as NO2
N SO2O
2 NPLI CS/ CEMS/VC-2025-15
CH4
O2
23 Envea India Private Limited Verification Certificate CO2
24 Envea India Private Limited Verification Certificate SC 600T/ PCME Stack 602 PM NPLI CS/ PM-CEMS/VC-2025-17
25 Envea India Private Limited Verification Certificate PCME QAL 182 WS PM NPLI CS/ PM-CEMS/VC-2025-18
26 Forbes Marshall Verification Certificate D-CEM2100 PM NPLI CS/ PM-CEMS/VC-2025-19
CO
NO NPLI CS/ CEMS/VC-2025-20
27 Forbes Marshall Verification Certificate FMGCEM40XX (GCEM-40) SO2
List Updated on 10.12.2025
28 SARTECH INTL (LAND UK) Verification Certificate 4500 MkIII PM NPLI CS/PM-CEMS/VC-2025-29
Envirozone Pvt. Ltd.
Provisional Letter
29 (Envirozone Instruments & EZ 320-PM PM NPLI CS/PM-CEMS/PLoC-2025-30
of
Equipments Pvt. Ltd.)
confirmation
ACOEM ECOTECH
30 INDUSTRIES PRIVATE Verification Certificate Serinus 30 CO NPLI CS/CEMS/VC-2025-31
LIMITED
ACOEM ECOTECH
NO
31 INDUSTRIES PRIVATE Verification Certificate Serinus 40 NPLI CS/CEMS/VC-2025-32
NO2
LIMITED
ACOEM ECOTECH
32 INDUSTRIES PRIVATE Verification Certificate Serinus 50 SO2 NPLI CS/CEMS/VC-2025-33
LIMITED
.. to be cont. in next pageSr. No. Certificate Holder Certificate Type Model No. Gases/Dust Certificate Number
List Updated on 12.12.2025
33
Bhoomi Process Management Pvt. Ltd. Provisional Lette r of
PM
confirmation BI 7010 NPLI CS/PM-CEMS/PLoC-2025-34
34
Bhoomi Process Management Pvt. Ltd. Provisional Lette r of
PM
confirmation BI 7020 NPLI CS/PM-CEMS/PLoC-2025-35
35 Advance Enviro Solutions Verification Certificate Gaz-CEMS and Gaz-
SP OM
x NPLI CS/CEMS/VC-2025-36 *5
NOx
SPM
36 Envirozone Pvt. Ltd. (Envirozone Provisional Letter of EZ 320-NDIR
NSO O2
NPLI CS/CEMS/PLoC-2025-37
CO
Instruments & Equipments Pvt. Ltd.) confirmation
CO
NO
37 ABB India Limited Verification Certificate EL 3000-Uras26
CSO O2
2 NPLI CS/CEMS/VC-2025-38
O2 (Electrochemical)
O2 (Parama gnetic)
CO
NO
NO2
N2O
SO2
HCl
HF
NH3
38 ABB India Limited Verification Certificate ACF 5000 Series H2O NPLI CS/CEMS/VC-2025-39
CO2
H2CO
CH4
TOC (FID)
O2 (ZrO 2)
CO
NO
NO Version (L)
SO2
39 ABB India Limited Verification Certificate AO 2000 Series N2O NPLI CS/CEMS/VC-2025-40
CO2
O2
40 Verification Certificate NPLI CS/CEMS/VC-2025-41
Waste Gas Velocty
ABB India Limited FMD 09 Series
CO
CO2
NO
NO2
N2O
N SOH 23
HCl
41 ABB India Limited Verification Certificate MCA 10 Series NPLI CS/CEMS/VC-2025-42
H2O
CH4
TOC
O2
CH2O
42 ABB India Limited Verification Certificate PFM 20/20F Series NPLI CS/PM-CEMS/VC-2025-43
PM
*5 Henceforth, for verification certificate no. NPLI CS/CEMS/VC-2025-36, a revised copy of the certificate is enforced.Sr.
No. Certificate Holder Certificate Type Model No. Gases/Dust Certificate Number
Updated on 27.12.2025
Engineering and
Provisional Letter NPLI CS/PM-CEMS/PLoC-
43 Environmental EE-SPM-100-BS PM
of confirmation 2025-44
Solutions Pvt. Ltd.
Provisional Letter NPLI CS/PM-CEMS/PLoC-
44 Aadhav Intech LM-318 PM
of confirmation 2025-45
SWAN
Provisional Letter NPLI CS/PM-CEMS/PLoC-
45 environmental Pvt. LM3189 PM
of confirmation 2025-46
Ltd.
CO
CO
2
SO
2
NO
NO
2
Thermo Fisher
Verification N O
46 Scientific India Pvt. MAX-iR FTIR 2 NPLI CS/CEMS/VC-2025-47
Certificate
Ltd. NH 3
HF
HCl
CH
4
H O
2
VOC
Thermo Fisher NO
Verification
47 Scientific India Pvt. 42i NPLI CS/CEMS/VC-2025-48
Certificate
Ltd. NO
2
Thermo Fisher
Verification
48 Scientific India Pvt. 43i SO NPLI CS/CEMS/VC-2025-49
2
Certificate
Ltd.
UNISEARCH INDIA HF
Verification
49 INSTRUMENTS LasIR HF-HCl-H2O HCl NPLI CS/CEMS/VC-2025-50
Certificate
PRIVATE LIMITED H O
2
UNISEARCH INDIA
Verification
50 INSTRUMENTS UIIPL–DOAS-SO2 SO2 NPLI CS/CEMS/VC-2025-51
Certificate
PRIVATE LIMITED
UNISEARCH INDIA NH
Verification LasIR for NH3 3
51 INSTRUMENTS NPLI CS/CEMS/VC-2025-52
Certificate and H2O H O
PRIVATE LIMITED 2
PM
Verification Gaz-CEMS and
52 Eco System SOx NPLI CS/CEMS/VC-2025-53
Certificate Gaz-SPM
NOx
SO
2
Analyser
Verification NO
53 InstrumentCo. Pvt. ZRE - ZRE/ZFK 7 NPLI CS/ CEMS/VC-2025-54
Certificate CO
Ltd.
O2 (Pa)Sr.
No. Certificate Holder Certificate Type Model No. Gases/Dust Certificate Number
Updated on 27.12.2025
O2 (Zi)
Vasthi Instruments Provisional Letter NPLI CS/PM-CEMS/PLoC-
54 VBDM-1500 PM
Pvt. Ltd. of confirmation 2025-55
Vasthi Instruments Verification
55 Vair-9001 SO NPLI CS/CEMS/VC-2025-56
2
Pvt. Ltd. Certificate
Vasthi Instruments Verification
56 Vair-9002 NO NPLI CS/CEMS/VC-2025-57
2
Pvt. Ltd. Certificate
CO
Envea India Verification
57 HCL NPLI CS/CEMS/VC-2025-58
Private Limited Certificate MIR9000
SO2
NO
Envea India Verification
58 GRAPHITE 52M TOC NPLI CS/CEMS/VC-2025-59
Private Limited Certificate
GREEN ENVIRO SO 2
Verification
59 INTERNATIONAL CEMS-2000 NO NPLI CS/CEMS/VC-2025-60
Certificate
PVT LTD. O
2
SWAN SO
2
Provisional Letter
60 environmental Pvt. SGA-900 NO NPLI CS/CEMS/PLoC-2025-61
of confirmation
Ltd. CO
SO
2
NO
Set CEM CERT II
Adage Automation Verification CO
61 7MB1957 NPLI CS/CEMS/VC-2025-62
Private Limited Certificate O
2
(Ultramat 23)
NOx
CO
2
CO
NO
SO
Set CEM CERT II 2
Adage Automation Verification
62 7MB1957 NO NPLI CS/CEMS/VC-2025-63
2
Private Limited Certificate
(Ultramat 6) O
2
CO
2
NOx
NH3
Adage Automation Verification
63 LDS 6 7MB6121 H2O NPLI CS/CEMS/VC-2025-64
Private Limited Certificate
HCLContact Details of Certificate Holders (updated 27.12.2025
Sr.
Certificate Holder Email Contact No.
No.
1 PRIMA Equipment operations@primaequipment.com 8238030134
2 NEVCO Engineers Pvt Ltd adish.kapur@nevcoengineers.com 9873246469
3 Sintrol Oy vikram.singh@sintrol.com 9811676061
4 ACE GAS ANALYSERS PRIVATE LIMITED sam@acegasanalysers.com 9987824250
5 Endress+Hauser India yugeshwari.devrukhkar@endress.com 8655715821
a.srivastava@envea.global/
6 Envea India Private Limited 9311103004
r.kumar@envea.global
7 Horiba India Pvt. Ltd. kunal.soni@horiba.com 9616747400
Envirozone Pvt. Ltd. (Envirozone
8 salesenvirozone@gmail.com 8076751198
Instruments & Equipments Pvt. Ltd.)
9 DURAG India Instrumentation Pvt. Ltd. veer.kumar@durag.com 72045 37762
10 Forbes Marshall environ@forbesmarshall.com 9503560565/98231996711 SARTECH INTL (LAND UK) in.sartech@gmail.com 9840082710
ACOEM ECOTECH INDUSTRIES PRIVATE
12 harsh.dixit@acoem.com 7229044507
LIMITED
13 Bhoomi Process Management Pvt. Ltd. nayan@bhoomiltd.com 86522 97579
14 Advance Enviro Solutions yash@advanceenviro.co.in 9891306306
15 ABB India Limited salman.azeem@in.abb.com 9540190932
Engineering and Environmental
16 Hamza@enggenv.com 9540990415
Solutions Pvt. Ltd.
17 Aadhav Intech admin@aadhavintech.com 9629466446
18 SWAN environmental Pvt. Ltd. karthik.b@swanenviron.in 9642225195
19 Thermo Fisher Scientific India Pvt. Ltd. chandan.yadav@thermofisher.com 9810295553
UNISEARCH INDIA INSTRUMENTS
20 service@unisearch-india.com 9025406630
PRIVATE LIMITED
21 Eco System vppcpcb@gmail.com 9882810053
22 Analyser InstrumentCo. Pvt. Ltd. aicpl.india@gmail.com 9772230061
23 Vasthi Instruments Pvt. Ltd. prakash@vasthi.com 7382708685
GREEN ENVIRO INTERNATIONAL PVT
24 sharon@greenenviro.co.in 8247649007
LTD.
25 Adage Automation Private Limited pm@adage-automation.com 9867630715