Name: NextPM
Brand: TERA Sensor

NextPM internal architecture showing the air path, optical elements and outlet flow

MEASUREMENT ARCHITECTURE

Designed around the known limitations of compact optical PM measurement

Compact optical sensors must operate under changing humidity, aerosol and installation conditions. These factors can affect particle response, airflow stability, contamination and measurement consistency over time.

NextPM combines active environmental management with a patented optical and fluidic architecture designed to provide more reliable particle data across demanding OEM applications.

Active humidity management

The incoming aerosol is thermally managed before optical measurement to reduce the influence of humidity and hygroscopic particle growth.

Dual-angle optical detection

Two optical detection angles provide additional information about particle scattering and support a more stable representation of the measured aerosol.

Active and monitored airflow

Integrated airflow generation and monitoring provide controlled sampling conditions without relying only on uncontrolled natural convection.

Protection against contamination

The internal architecture limits the entry of large particles and reduces contamination risks in long-term monitoring applications.

2026 update

Independent evaluations and published performance data

NextPM has been evaluated in laboratory and field conditions by independent organizations and research teams. The data below summarizes publicly available results for NextPM and selected particulate matter sensors. Test conditions and sources are provided for each dataset.

NextPM (€69): PM2.5 accuracy 9.5/10, Humidity resilience 9.5/10, Low noise 9/10, Inter-unit consistency 10/10, Coarse fraction 3/10, Price (affordability) 9/10, Size channels / ML 7/10, Dynamic response 5/10 · OPC-N3 (€350–450): PM2.5 accuracy 7/10, Humidity resilience 3/10, Low noise 4/10, Inter-unit consistency 6/10, Coarse fraction 1/10, Price (affordability) 3/10, Size channels / ML 9/10, Dynamic response 9.5/10 · SPS30 (€45): PM2.5 accuracy 7.5/10, Humidity resilience 4/10, Low noise 6/10, Inter-unit consistency 7/10, Coarse fraction 0.5/10, Price (affordability) 9.5/10, Size channels / ML 4/10, Dynamic response 7/10 · SDS011 (€30): PM2.5 accuracy 5/10, Humidity resilience 3/10, Low noise 3/10, Inter-unit consistency 4/10, Coarse fraction 0.5/10, Price (affordability) 10/10, Size channels / ML 1/10, Dynamic response 2/10 · OPC-R2 (€280): PM2.5 accuracy 7.5/10, Humidity resilience 3/10, Low noise 5/10, Inter-unit consistency 5.5/10, Coarse fraction 1/10, Price (affordability) 4.5/10, Size channels / ML 8.5/10, Dynamic response 9/10 · PMS5003 (€15–25): PM2.5 accuracy 7/10, Humidity resilience 2.5/10, Low noise 3/10, Inter-unit consistency 7/10, Coarse fraction 0.5/10, Price (affordability) 9.8/10, Size channels / ML 3/10, Dynamic response 8/10

Results originate from different studies and test conditions and should not be interpreted as a single standardized head-to-head test. Score calculated from published data — methodology available below.

View methodology and sources

Sources and methodology

Scoring methodology — how each axis is calculated

All scores derived from quantitative results in the cited studies. No subjective weighting. Normalized linearly 0–10 within tested population.

PM2.5 accuracy : R² values: lab weight 40%, field 60%. Scale: R²=0.50→0, R²=1.00→10.

Humidity resilience : Water aerosol rejection ratio + field RH slope. Active heater = strong advantage. No heater = capped at 4.

Low noise : Clean-air std dev + max outlier [4]. Lower = better. Integer-only output penalized.

Inter-unit consistency : Between-Sensor Uncertainty (BSU) [5]. Scale: BSU=0→10, BSU=4→0.

Coarse fraction : R² for PM10−PM2.5 from VITO [5]. Linear: R²=0→0, R²=1→10.

Price (affordability) : Linear inverse: €15→10, €450→0. OEM unit prices.

Size channels / ML : Real channels (50%) + demonstrated discrimination (50%). ML adds to score.

Dynamic response : Inverse of t10-90 [7]. Faster = higher. PMS5003 from datasheet.

Evidence per axis

PM2.5 accuracy 9.5

NextPM 9.5 Lab R²>0.99 vs T640x across 9 T/RH conditions [2]. Field R²=0.88–0.95 (California, 2mo) [1], R²=0.82–0.98 (Marseille, 2mo) [3], R²=0.87 (Antwerp, 3mo) [5]. Lab R²=1.00 VITO chamber (best of all) [5].
OPC-N3 7 Good in high-PM but drops in mild pollution. OPC-N2 R²=0.975 strong pollution, <0.5 mild [4]. Not directly tested vs FEM in NextPM studies.
SPS30 7.5 Lab R²=0.99 (VITO). PM2.5 accuracy 53–56% [5]. R²≥0.97 for multiple aerosol types [11].
SDS011 5 Strong size dependency. 2/5 units malfunctioned during IUTA testing [7].
OPC-R2 7.5 R²=0.96 lab. Detection efficiency closest to 1 in IUTA study [7].
PMS5003 7 Lab R²≥0.97 [11]. Field R²=0.78–0.90 [10]. Drops to 0.18–0.72 mild pollution/wildfire [9]. Accuracy 86–93% fine PM, poor >2.5µm [12].

Humidity resilience 9.5

NextPM 9.5 Patented internal heating (<60% RH). Water aerosol max PM10=11.3µg/m³ vs 103.3 OPC-N3 (9×) [4]. Field RH slope: 0.10 vs 0.63 (6×) [4]. AQ-SPEC: no climate effect 5–35°C, 15–65% RH [2].
OPC-N3 3 No heater. Water aerosol max PM10=103.3µg/m³. Field RH slope: 0.63, R²=0.248 [4].
SPS30 4 No heater. PM overestimation at RH>60% [5][13].
SDS011 3 No heater. Overestimated up to 38× when aerosols not dried [7].
OPC-R2 3 No heater. Similar to OPC-N3 [7].
PMS5003 2.5 No heater. Accuracy drops >50% RH. Overestimates ~30–40% ambient [10][9]. ±10–15µg/m³ specified accuracy [12].

Low noise 9

NextPM 9 PM2.5=0.3±0.2, PM10=0.5±0.4µg/m³. Max outlier: 2.5µg/m³. Field PM10 σ: 5.6. Score +4/7 criteria [4].
OPC-N3 4 PM2.5=0.4±0.5, PM10=0.6±1.4µg/m³. Max outlier: 17.6µg/m³ (7×). Field PM10 σ: 12.1. Score −4 [4].
SPS30 6 Moderate noise. Better than OPC-N3. Floating-point output [7][11].
SDS011 3 High variability. Variable t10-90 (5–24s). 2/5 malfunctioned [7].
OPC-R2 5 First bin overestimates at low conc. Moderate noise [7].
PMS5003 3 Integer-only (1µg/m³ resolution), spiky, frequent zeros. Less precise than SPS30 [11]. Count data "not reliable" [11].

Inter-unit consistency 10

NextPM 10 BSU=0.1µg/m³ — lowest of 8 systems [5]. Inter-unit R²>0.99 [3]. CEN: "individual calibration not necessary" [8].
OPC-N3 6 Moderate BSU. Outlier behavior differs between units [4][7].
SPS30 7 BSU=0.3µg/m³ — 3× higher than NextPM [5]. Good precision Tryner lab [11].
SDS011 4 2/5 malfunctioned (IUTA). Significant inter-unit variability [7].
OPC-R2 5.5 BSU=1.6µg/m³ lab [7].
PMS5003 7 Batch R²>0.99 for 8 units. But "less precise than SPS30" [11]. Frequent A/B disagreement in PurpleAir [11].

Coarse fraction 3

NextPM 3 R²=0.3 — only sensor with measurable coarse sensitivity. Dual-angle 45°+90° [5].
OPC-N3 1 R²≈0 despite 24 bins. Truncated viewing angle [5][7].
SPS30 0.5 R²≈0. Fixed PSD >1µm [5][13].
SDS011 0.5 Fixed PSD. No coarse differentiation [7].
OPC-R2 1 R²≈0 despite 16 bins [5][7].
PMS5003 0.5 Bin 2.5–10µm "noisy and inaccurate" [13]. Misclassifies to smallest bin [9]. PM10 R²=0.34–0.45 [10].

Price (affordability) 9

NextPM 9 €69 (Standard). Also: Verified €82, Adjusted ~€120 [14].
OPC-N3 3 €350–450. 5–6× NextPM [7].
SPS30 9.5 ~€45 [7].
SDS011 10 ~€30. Cheapest tested [7].
OPC-R2 4.5 ~€280 [7].
PMS5003 9.8 €15–25. Most deployed globally (PurpleAir, Airly) [9][10].

Size channels / ML 7

NextPM 7 5 real channels (0.3–10µm). Fractionation 0.5–5µm better than SPS30 [7]. ML: 82.4% pollutant ID [6].
OPC-N3 9 24 bins. True spectrometer. Best size resolution [7].
SPS30 4 5 NC channels. Fixed PSD >1µm. "Overlapping bins = generalized calibration" [13][7].
SDS011 1 PM2.5/PM10 only. No channels [7].
OPC-R2 8.5 16 bins. Good size distribution reproduction [7].
PMS5003 3 6 bins but fixed PSD. Count data "remained constant" across all PSL sizes, "not reliable" [11][13][12].

Dynamic response 5

NextPM 5 t10-90=8.1±0.1s. Internal smoothing → smoother signal, slower response [7].
OPC-N3 9.5 t10-90=1.6s. Fastest tested [7].
SPS30 7 t10-90=4.6s [7].
SDS011 2 5–24s variable. Inconsistent [7].
OPC-R2 9 t10-90=1.8s [7].
PMS5003 8 ~2.3s stable, 200–800ms fast (datasheet). Fast but noisier [9].

Score summary — active sensors

Axis	NextPM	OPC-N3	SPS30	SDS011	OPC-R2	PMS5003
PM2.5 accuracy	9.5 2, 1, 3, 5	7 4, 7	7.5 5, 11	5 7	7.5 7	7 11, 10, 9, 12
Humidity resilience	9.5 4, 2, 5	3 4	4 5, 13	3 7	3 7	2.5 10, 9, 12
Low noise	9 4	4 4	6 7, 11	3 7	5 7	3 11, 9
Inter-unit consistency	10 5, 3, 8	6 4, 7	7 5, 11	4 7	5.5 7	7 11, 12
Coarse fraction	3 5	1 5, 7	0.5 5, 13	0.5 7	1 5, 7	0.5 13, 10, 12
Price (affordability)	9 14	3 7	9.5 7	10 7	4.5 7	9.8 9, 10
Size channels / ML	7 7, 6	9 7	4 7, 13	1 7	8.5 7	3 11, 13, 12
Dynamic response	5 7	9.5 7	7 7	2 7	9 7	8 9
Total	62/80	42.5/80	45.5/80	28.5/80	44/80	40.8/80

References

Only the references cited by the selected sensors are listed.

1 South Coast AQMD (2021). Field Evaluation — Tera Sensor NextPM. AQ-SPEC Program. open source document
2 South Coast AQMD (2022). Laboratory Evaluation — Tera Sensor NextPM. AQ-SPEC Program. open source document
3 Wortham, H. et al. (2021). In Field Study of NextPM Sensor. Report RR-20210112-01. AtmoSud / LCE, Aix-Marseille University. open source document
4 Alvarez Cruz, A., Schalm, O. et al. (2025). Benchmarking Low-Cost PM Sensors. Atmosphere, 16, 172. open source document
5 Hofman, J. et al. (2024). Portable Sensors for Dynamic Exposure Assessments. Sensors, 24, 5653. open source document
6 Azeraf, E. et al. (2025). Real-Time Pollutant Identification through Optical PM Micro-Sensor. arXiv:2503.10724v1. open source document
7 Nothhelfer, M. et al. (2025). Performance Evaluation of 5 Low-Cost PM Sensors for Monodisperse Test Aerosols. Aerosol Air Qual. Res., 25:17. open source document
8 Morawska, L., Asbach, C. & Patel, H. (2025). Application of PM2.5 LCS for IAQ Compliance Monitoring. Aerosol Sci. Technol., 59(2), 1210–1220. open source document
9 Sayahi, T. et al. (2019). Long-term field evaluation of the Plantower PMS low-cost PM sensors. Environ. Pollution, 245, 932–940. open source document
10 AQ-SPEC (2016). Field Evaluation — PurpleAir PA-II (Plantower PMS5003). South Coast AQMD. open source document
11 Tryner, J. et al. (2020). Lab evaluation of low-cost PurpleAir PM monitors. Atmos. Meas. Tech., 13, 4407–4420. open source document
12 Levy Zamora, M. et al. (2019). Field and Laboratory Evaluations of the Low-Cost Plantower PM Sensor. Environ. Sci. Technol., 53(2), 838–849. open source document
13 Kuula, J. et al. (2020). Response characterization of an inexpensive aerosol sensor. Atmos. Meas. Tech., 13, 2507–2529. open source document
14 TERA Sensor (2026). Product Catalogue. Groupe TERA, Rousset, France. open source document

This comparison compiles data exclusively from independent third-party evaluations. No proprietary data from any sensor manufacturer has been used for scoring. All metrics are traceable to the cited references. March 2026.

Technical specifications

Key optical, environmental, mechanical and integration specifications for the standard NextPM configuration. For controlled sampling, remote sampling or higher concentrations, explore NextPM Advanced.

Designation	Values	Unit
GENERAL
Technology	Optical
Targeted pollutants	Particulate Matter
Outputs	PM1PM2.5PM10TSP 1,2Channel: 0.3 -0.5 μm1Channel: 0.5 - 1 μm1Channel: 1 - 2.5 μm1 Channel: 2.5 - 5 μm1Channel: 5 - 10 μm1Temperature 3Relative Humidity	μg/m3 & pcs / Lμg/m3 & number of particles / Lnumber of particles / L°C%
Airflow	2.5	L/mn
Size (l * w * h)	Annex 1	mm
Lifetime (MTTF)1	Up to 10	years
PERFORMANCE
Particle Size detection range	0.3 - 10	μm diameter
Detection efficiency with 0.3 μm diameter particles	>50	%
Concentration detection range / PM10 - PM2,5 - PM1	0 - 1000	μg/m3 (Arizona dust A1 equivalent)
	>1000	g/m3 (Arizona dust A1 equivalent)
Detection Limit	< 1	μg/m3 (Arizona dust A1 equivalent)
Linearity error	< 5	%
Repeatability error 2	< 3	%
Refresh rate	1/10/60	sec.
Warm-up time	10	sec.
Temperature influence	< 0.01	μg/ m3 /°C
0°C to 30°C	0	%/°C
-20°C to 0°C	< + 1.0	%/°C
30°C to 70°C	< - 0.8	%/°C
ELECTRIC SPECIFICATIONS
Power supply	5	VDC
Power consumption in operation	< 80300	mAmA (Maximum)
Power consumption in Sleep Mode	< 5	mA
COMMUNICATION
UART, Modbus
OTHER
Operating conditions	-20 to +70253 to 343	°CK
	0 - 95 uncondensed	%
	500 to 1 500	hPa
Storage conditions	-20 to +70	°C
	0 - 95 uncondensed	%
	500 to 1500	hPa
Certifications	CE
	RoHS compliant
Dimensions and weight	L 62 mm x W 52.5 mm x H 23.6 mm \| 45 g
	L 2.44 / W 2.05 / H 0.91 inches \| 1.59 Oz

OEM INTEGRATION

Everything needed to integrate NextPM into your product

NextPM is supplied with the technical resources required for mechanical, electronic and software integration. TERA Sensor’s engineering team can also review the intended installation and operating conditions before prototype development.

Download the datasheet↗ Access the technical GitBook↗ View the communication protocol↗ Download 3D files↗ View mechanical integration guidelines↗ Contact an integration engineer→

PERFORMANCE OPTIONS

Select the level of performance documentation your project requires

NextPM is available with three levels of performance documentation. Move from the standard production configuration to batch-level verification or individual adjustment according to your project’s quality and traceability requirements.

	STANDARD NextPM Standard	BATCH VERIFIED NextPM Verified	HIGHEST DOCUMENTED PERFORMANCE NextPM Adjusted
Positioning	Standard production configuration	Batch-verified performance	Individually adjusted performance
Production controls	Standard production controls	Standard controls + batch verification	Standard controls + individual characterization
Verification level	Production level	Batch level	Individual sensor level
PM2.5 documented deviation under specified laboratory conditions	Standard specification	< 20%	< 10%
Individual adjustment	—	—	✓
Adjustment points	—	—	3 points
Performance documentation	Standard product documentation	Batch performance certificate	Individual performance certificate
Serial-number traceability	✓	✓	✓
Best suited for	Cost-efficient OEM integration	Projects requiring additional batch-level assurance	Demanding applications requiring the highest documented performance
	Request NextPM Standard	Request NextPM Verified	Request NextPM Adjusted

The stated performance levels apply under the test conditions described in the corresponding documentation. Optical PM response can vary with aerosol properties and environmental conditions.

INDEPENDENT PERFORMANCE DATA

Performance supported by independent evaluations and published studies

NextPM performance has been assessed through external evaluation programmes and independent scientific studies. These results provide application-specific evidence beyond manufacturer specifications alone.

AQ-SPEC evaluation

South Coast AQMD — independent field and laboratory evaluation program.

PM2.5 correlation up to R² = 0.95 and PM10 up to R² = 0.68 against reference-grade instruments, with 100% data recovery over the evaluation period.

View report ↗

South Korean Class 1 certification

Korea Conformity Laboratories (KCL) — Certificate of Performance for PM2.5 air sensors, No. LS24-00003.

Grade 1 (highest grade), 80.7% accuracy against reference monitoring data, issued under the Special Act on the Reduction and Management of Fine Dust.

View certificate ↓

Peer-reviewed publications

4 peer-reviewed studies evaluating NextPM performance.

Topics: benchmarking against reference and low-cost sensors, portable exposure assessment, response to monodisperse aerosols, IAQ compliance monitoring.

View bibliography ↑

Field and comparative evaluations

Outdoor and laboratory environments — France (LCE / AtmoSud) and California (South Coast AQMD).

Multi-month field deployments alongside reference-grade instruments, contextualized by aerosol type and test conditions.

View methodology ↑

Korea Conformity Laboratories Certificate of Performance for NextPM, No. LS24-00003, Grade 1

Korea Conformity Laboratories performance evaluation results for NextPM — Grade 1 across all criteria

Certificate of Performance No. LS24-00003, issued 24 December 2024 by Korea Conformity Laboratories under Article 24-1 of the Special Act on the Reduction and Management of Fine Dust and Article 16-3 of its Enforcement Regulations.

APPLICATIONS

Where NextPM is used

NextPM is designed for integration into connected monitoring devices, distributed sensor networks and environmental measurement systems.

Environmental Air Quality

Increase spatial and temporal coverage with compact particle sensors designed for monitoring networks and OEM systems.

Explore environmental monitoring

HVAC & Filtration

Measure particles in ventilation and duct systems where sampling conditions and system integration must be considered together.

Explore HVAC applications

Industrial Monitoring

Monitor particle conditions to investigate process variations, filtration, extraction and production environments.

Explore industrial monitoring

FAQ

What does NextPM measure?

NextPM measures PM1, PM2.5 and PM10 mass concentrations and provides particle information across five size channels. It is an optical particle sensor designed for integration into OEM monitoring devices.

How does NextPM manage humidity?

NextPM actively manages the incoming aerosol before optical measurement to reduce the influence of humidity and hygroscopic particle growth. Aerosol composition and environmental conditions must nevertheless remain part of data interpretation.

What is the difference between NextPM Standard, Verified and Adjusted?

NextPM Standard is the standard production configuration. NextPM Verified includes additional batch-level performance documentation. NextPM Adjusted is individually characterized and adjusted under defined test conditions for applications requiring tighter documented PM2.5 performance.

What is the difference between NextPM and NextPM Advanced?

NextPM includes its own airflow architecture for compact OEM integration. NextPM Advanced uses an external pump and controlled sampling architecture for remote sampling, application-specific airflow and higher particle concentrations.

Can NextPM be installed outdoors?

NextPM can be integrated into outdoor monitoring equipment, but it must be protected by an appropriate enclosure and air-inlet design. Water ingress, condensation, solar radiation, temperature and airflow must be considered in the final system.

Can NextPM be installed inside an HVAC system?

NextPM can be integrated into HVAC-related equipment when the sampling and pressure conditions remain compatible with its architecture. For direct in-duct monitoring, PMDuct or a controlled-sampling architecture may be more appropriate.

Does NextPM require calibration?

The appropriate verification or adjustment strategy depends on the application, aerosol and expected performance. TERA Sensor can help define a suitable approach for prototype validation and series production.

Is NextPM a reference or regulatory instrument?

No. NextPM is an OEM optical particle sensor. Its data can support continuous monitoring and comparative analysis, but the final system and its intended use determine the applicable validation and regulatory requirements.

Is NextPM suitable for cleanroom classification?

No. NextPM is not intended for ISO cleanroom classification. SafyrOPC should be used when ISO 21501-4 particle counting is required.

What technical resources are available?

Datasheets, communication documentation, mechanical information, 3D files and integration guidance are available through the technical resources section. TERA Sensor engineers can also support application-specific integration.

What quantities can TERA Sensor supply?

NextPM is available for prototype development, pilot production and series manufacturing. Contact TERA Sensor with the expected quantity and project schedule to receive the appropriate commercial proposal.

Can I buy a small quantity of NextPM without a quotation?

Yes. For one to a few units needed quickly for a bench test or first evaluation, NextPM is available through authorized distributors. See where to buy NextPM for direct-quotation and distributor options.

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