SP Series
Spirometry accuracy depends on a pressure baseline that doesn’t drift, and most sensors need routine recalibration to preserve it. The SP Series eliminates that requirement with Z‑Track zero‑drift technology, combining position insensitivity, 2‑millisecond response, and 0.05% accuracy purpose‑built for handheld and clinical spirometers.
2 ms
response time
0.05%
accuracy
Z-Track auto
zero technology
Position
insensitivity
SP Series Overview
Most pressure sensors used in spirometry slowly lose their zero, requiring periodic recalibration and risking drift between patient readings. The SP Series was built on the NimbleSense architecture to break that tradeoff: proprietary Z‑Track technology continuously corrects zero drift in the background, eliminating manual recalibration while preserving a rock‑solid baseline. Paired with position insensitivity, an industry‑leading noise floor, and a 2‑millisecond response, the SP Series delivers spirometry‑grade performance that conventional industrial sensors cannot match, purpose‑built for handheld and clinical spirometers as well as FOT systems.
Z-Track auto zero technology
Zero drift accumulates between patient readings and, if uncorrected, shifts the measurement baseline, degrading the accuracy of FVC, FEV1, and peak flow results. Z‑Track continuously monitors and corrects zero drift without pausing for recalibration, maintaining a stable baseline across every reading and avoiding interruptions to the clinical workflow. This eliminates the manual recalibration routine required by competing sensor designs and removes a systematic source of measurement error from every spirometry test.
Position insensitivity (SP210)
Handheld spirometers are held in different orientations by different patients, and a sensor that responds to tilt introduces a systematic error that varies from test to test. The SP210 is position‑insensitive, delivering consistent measurements regardless of device orientation. Results align whether the spirometer is held horizontally, vertically, or at any intermediate angle, eliminating orientation as a source of variability in handheld spirometry and FOT readings.
Multi-Range technology
Four selectable pressure ranges per device allow the SP Series to cover the low differential pressures of tidal breathing and quiet airflow at ±250 Pa, as well as the higher pressures of forced maneuvers up to ±40 kPa, without stocking separate sensor variants for each measurement type. The active range is easily selectable, giving spirometer designers the flexibility to support patients from children to elite athletes on a single device platform while optimizing performance across different test protocols.
2 ms response & 250 Hz bandwidth
Spirometry tests such as FEV₁ and peak expiratory flow produce rapid pressure transitions that a slow sensor rounds off, systematically underreporting peak values. The SP Series 2‑millisecond update rate and 25 to 250 Hz programmable bandwidth capture the full dynamics of forced expiratory tests, including the sharp onset of peak flow and rapid flow transitions that differentiate obstructive from restrictive patterns in the spirometry curve.
SP Series Product Offerings
Common Device Features: 3.3V supply
Long-Term Stability is measured after first 12 months
Short-Term Error Band (STEB) is measured over 24 hours, after auto-zero
Common Specifications
- Z-Track virtually eliminates zero drift
- 16-bit resolution each range
- Ultra low noise, 19-bit effective resolution
- Very fast warm-up time
- Low power consumption
- Enhanced EMI immunity
- Temperature-compensated from 0°C to 50°C
- Supply voltage compensation
- Fully integrated compensation math
- Standard I2C and SPI interfaces
Features Matrix
| Product | Z-Track Auto Zero | Position Insensitivity | Advanced Digital Filtering |
|---|---|---|---|
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Evaluation and Accessories
| Evaluation hardware and accessories | |||
|---|---|---|---|
 | Evaluation board EB02 supports all SP Series products. | ||
 | SP Series evaluation kit, EK03-SP, includes evaluation board and one unit of each SP Series sensor. | ||
 | Right angle adapters for reducing total Z-height. KP-ROR includes o-rings for an airtight seal. | ||
Resources
| Data Sheet and Other Series Documentation | Version | Date | Download |
|---|---|---|---|
| SP Series Data Sheet (DS-0002) | E | August 2024 |  |
| Data Sheet Definitions (AN-0011) | A | February 2024 | |
| Pressure Sensor Handling & Assembly Instructions (AN-0010) | C | February 2026 | |
| How to use Z-Track Technology (AN-0012) | A | March 2025 | |
| Tubing Recommendations for Pressure Ports (AN-0014) | A | March 2026 | |
| SP Series Product Brief (PB-0003) | F | April 2023 | |
| Unique Features for Medical Applications (MB-0002) | C | May 2025 | |
| Evaluation Software | Version | Date | Download |
|---|---|---|---|
| EK03-SP and EB02 Evaluation Software (PRT-0279) | G | December 2025 |  |
| EB01 Evaluation Software (PRT-0143) | E | February 2024 | |
| Drawings and CAD Files | Version | Date | Download |
|---|---|---|---|
| SM02 Package for all SP Series Sensors (IGS and STEP files) | A | March 2023 | |
| KP-ROR Package for Right Angle Adapters (STEP file) | A | February 2024 | |
Download models in over 50 formats
| Catalogs and Compliance Documentation | Version | Date | Download |
|---|---|---|---|
| Product Ordering Guide (PL-0001) | X | May 2025 | |
| NimbleSense Capabilities Brochure (MB-0001) | B | April 2023 | |
| Product Catalog (MB-0004) | F | May 2025 | |
| Certificate of RoHS Compliance (CS-0001) | A | May 2019 | |
| Statement of REACH-253 Compliance (CS-0002) | E | May 2026 | |
| Statement on Use of Conflict Minerals (CS-0003) | A | May 2019 | |
| Certificate of California Proposition 65 Compliance (CS-0006) | A | May 2019 | |
Videos
Z-Track Technology
SP Series Benefits Summary
SP Series Frequently Asked Questions
How does Z-Track eliminate zero drift, and how is it different from a manual auto-zero?
Zero drift occurs when a pressure sensor’s “zero point” slowly shifts over time, even when no pressure is applied. Traditional systems address this by pausing tests to run a manual re‑zero routine. Z‑Track continuously monitors and corrects the sensor’s baseline in the background, keeping readings anchored without pausing for recalibration. In practice, this means the sensor remains accurate from one spirometry reading to the next without disrupting the clinical workflow or adding extra steps for staff.
What is the difference between the SP110 and SP210, and when should I choose the SP210?
Both the SP110 and SP210 cover the same pressure range from ±250 Pa to ±2500 Pa across four selectable ranges and include Z‑Track auto‑zero technology. The SP210 adds position insensitivity and delivers tighter accuracy: long‑term stability of 1.25 Pa versus 2 Pa, a short‑term error band of 0.75 Pa versus 1.25 Pa, and a total error band of 1.75 Pa versus 4 Pa. The SP110 is the right choice for bench‑top or stationary spirometers where orientation is fixed and tighter SP210 specifications are not required. The SP210 is the right choice for handheld spirometers that will be held in different orientations by different patients, or for any design where maximum accuracy is required regardless of orientation.
What is the SP160 designed for, and how does it apply to FOT?
The SP160 covers ±5 kPa to ±40 kPa, placing it above the pressure range of standard spirometry tests and within the range required for forced oscillation technique (FOT) measurements, as well as the higher pressures generated by athletes and patients with exceptional lung capacity. FOT assesses respiratory system impedance by superimposing small-amplitude oscillatory pressure signals on normal breathing, typically at frequencies from 5 to 20 Hz and at pressure amplitudes within the SP160’s range. The SP160’s 25 to 250 Hz bandwidth is sufficient to capture both the oscillatory pressure and flow signals used in FOT analysis and the higher-pressure dynamics seen in high-effort testing.
How does the 2ms response and 250 Hz bandwidth affect spirometry accuracy?
Spirometry tests, including FEV1, FVC, and peak expiratory flow, produce pressure transitions that rise and fall extremely quickly, especially at the onset of forced exhalation, when peak flow occurs within the first fraction of a second. A sensor with a slow update rate or limited bandwidth rounds off these transitions, systematically underreporting peak values and distorting the flow–volume curve, thereby affecting clinical interpretation. The SP Series, with a 2‑millisecond update rate and 25 to 250 Hz programmable bandwidth, captures the full dynamics of forced expiratory tests without attenuating the peak signal, preserving the accuracy of FEV1 and peak flow across the full range of patient effort levels.
How does zero drift in a pressure sensor translate into clinical measurement error?
A drifting spirometry sensor reads a different pressure at zero flow than it did at the start of the test, shifting the reference point for every flow and volume calculation. Over a clinic session or a series of back-to-back tests, that drift means the sensor systematically over- or under-reports flow relative to the original calibration. In results, it shows up as unexplained variability between sessions, small but consistent errors in FEV1 and FVC values, and difficulty meeting repeatability criteria across multiple efforts from the same patient. Z‑Track continuously removes this drift so the reference baseline at the end of the day is the same as it was at the start.
Can the SP160 be combined with the SP110 or SP210 in the same device platform?
Yes. A device that performs both standard spirometry and FOT measurements can combine an SP110 or SP210 for the low-pressure spirometry channel with an SP160 for the higher-pressure FOT channel. All SP Series models share the same SM02 package, I²C and SPI interfaces, and the same pin-out and software, so combining models on a single platform does not require separate mechanical designs or driver development for each sensor type. This makes the SP Series a practical foundation for combination respiratory diagnostic instruments that support both test modalities from a shared sensor platform.
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