DS4 Smart Digital Sensor
- 20×16.6 mm / 4.56 g / 3 pins
- UART 3.3V half-duplex, 9600 8N1
- Power ≤ 5 mW @ 5V
Best for: those who want to avoid analog circuitry, need digital ppm, and build battery / IoT devices.
EC Sense ES1 / ES4 / EC4 / Bare Sensor Cells
EC Sense Bare Sensor Cells
Solid-polymer electrochemical bare cells covering 20 toxic and harmful gas types across 79 models and 3 package platforms. Nanoamp-level analog output at the lowest cost per point — for high-volume instrument makers building their own transmitters. The AG1 all-gas family is equivalent to VOC/TVOC detection, a low-cost electrochemical alternative to PID.
- 79 Product Models
- 20 Gas Types Covered
- 3 Package Platforms
- < 0.7 g Lightest Package Weight
- -40~+55 ℃ Operating Temperature
Why Do Integrators Choose Bare Cells Over Modules?
A bare cell gives you a nanoamp analog signal and the lowest cost per point, but the amplifier, temperature compensation, gas calibration and firmware are all yours to build. It trades engineering time for per-point material savings — the larger the volume, the better it pays off.
| Aspect | Finished Detection Module | Bare Sensor Cell |
|---|---|---|
| Output Signal | Digital ppm + temp/RH (UART / I²C) | Nanoamp-level analog current |
| Calibration | Factory-calibrated with standard gas, data stored in flash | Calibrate yourself with a gas rig |
| External Circuitry | Integrated — power up and read | Bring your own amplifier + temp comp + ADC + firmware |
| Integration Effort | Power up in days | Weeks to months |
| Cost Per Point | Module price, higher | Cell price, lowest |
| Best For | Fast launch, small-to-mid volume, battery & IoT devices | High-volume instrument makers with in-house electronics & calibration |
Selection Guide
Five Steps to Specify a Bare Cell
Picking the wrong package costs more than picking the wrong range. Follow these five steps — each with an actionable decision rule.
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① Pick the gas
Pick your target from 20 industrial & environmental gases: CO, H₂S, H₂, NH₃, O₂, O₃, SO₂, NO₂, Cl₂, HCHO, HCN, PH₃, AsH₃, ETO, CH₃SH, C₂H₂, C₂H₄, F₂, Br₂, HF, HCl, ClO₂ — or the AG1 all-gas / VOC equivalent.
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② Fix the range
Size the ceiling to your threshold: a few times TLV for personnel safety, a tenth of LEL for leak detection, or full scale for emission monitoring. The AG1 family offers 10 / 200 / 1000 / 2000 ppm.
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③ Choose the package
ES1 = PPO ultra-compact SMD, < 0.7 g, for portable and space-constrained designs; ES4 = ABS standard package, < 6 g, easy pin-soldering; EC4 = ABS corrosion-hardened, < 8 g, purpose-built for Cl₂, F₂, HF, HCl, Br₂, ClO₂ and NH₃.
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④ Design the circuit
Use a 100 Ω load resistor to turn the nA current into a voltage, then amplify, temperature-compensate and feed an ADC. See the 'Recommended Load' and 'Sensitivity' fields in each EC Sense datasheet.
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⑤ Calibrate with gas
Calibrate zero and span with standard gas at the working temperature, then write the calibration into your instrument's flash. The AG1 family is referenced to CO (and Isobutene) and cross-responds to many reducing gases — see the cross-sensitivity table in the datasheet.
Which EC Sense Bare-Cell Line Do You Need?
ES1 / ES4 / EC4 are three package platforms; AG1 is an all-gas / VOC-equivalent family that spans ES1 and ES4. The package decides whether it fits your instrument; the gas family decides what you measure — choose them separately.
| Specification | ES1 Ultra-compact SMD | ES4 Standard Package | EC4 Corrosion-Hardened | AG1 All-Gas / VOC |
|---|---|---|---|---|
| Housing | PPO | ABS | ABS (corrosion-hardened) | PPO or ABS |
| Weight | < 0.7 g | < 6 g | < 8 g | < 0.7 g or < 6 g |
| Package Trait | Ultra-compact SMD, reflow solderable | Standard pin-type, easy soldering | Purpose-built for corrosive gases | Available in ES1 / ES4 packages |
| Gas Coverage | 20+ industrial & environmental gases | 20+ industrial & environmental gases | 7 corrosive / halogen gases | VOC / TVOC-equivalent all-gas |
| Typical Range | ppb to a few hundred ppm | ppb to a few hundred ppm | ppm-level corrosive gases | 10 / 200 / 1000 / 2000 ppm |
| Sensitivity Order | nA / ppm order | nA / ppm order | nA / ppm order | 11 – 55 nA / ppm |
| Best For | Portable / space-constrained modules | Standard module integration | Corrosive-environment monitoring | VOC / TVOC-equivalent detection |
| Expected Lifetime | > 2 – 5 years | > 2 – 5 years | > 2 years | > 3 years |
The AG1 all-gas family comes in both ES1 (PPO) and ES4 (ABS) packages, in 10 / 200 / 1000 / 2000 ppm ranges — see each product page and datasheet.
Where a Bare Cell Goes Next
Don't want to build the circuitry? The same EC Sense solid-polymer cell is already packaged into these plug-and-play smart modules — skip the amplifier and calibration, read concentration directly.
TB600B&C Detection Module
- 19 gases / 38 models / 108 order numbers
- Working current < 5 mA
- Range ppb to 10000 ppm
Best for: building a finished detector or online system with a ready module + temp/RH.
AG1 All-Gas → VOC/TVOC Use
- 10 / 200 / 1000 / 2000 ppm ranges
- ES1 and ES4 packages
- Calibrated with CO and Isobutene
Best for: VOC/TVOC measurement when a PID's price and UV lamp cost are out of reach.
The three downstream paths cover the full chain — bare cell → smart digital → detection module → gas cluster page. Not sure which path? Send us the target gas and form factor and we will give you a straight answer.
79 Bare-Cell Model Matrix
Grouped by target gas — click any model for its datasheet. The AG1 all-gas family is listed as its own group so the four ranges are easy to compare side by side.
VOC / All-Gas
- ES1-AG1-10 All-Gas / VOC Sensor ES1-AG1-10-01 Datasheet →
- ES4-AG1-10 All-Gas / VOC Sensor ES4-AG1-10-01 Datasheet →
- ES1-AG1-200 All-Gas / VOC Sensor ES1-AG1-200-01 Datasheet →
- ES4-AG1-200 All-Gas / VOC Sensor ES4-AG1-200-01 Datasheet →
- ES1-AG1-1000 All-Gas / VOC Sensor ES1-AG1-1000-01 Datasheet →
- ES4-AG1-1000 All-Gas / VOC Sensor ES4-AG1-1000-01 Datasheet →
- ES1-AG1-2000 All-Gas / VOC Sensor ES1-AG1-2000-01 Datasheet →
- ES4-AG1-2000 All-Gas / VOC Sensor ES4-AG1-2000-01 Datasheet →
Arsine
Methyl Mercaptan
Carbon Monoxide
- ES1-CO-10 Carbon Monoxide Gas Sensor ES1-CO-10-01 Datasheet →
- ES1-CO-100 Carbon Monoxide Gas Sensor ES1-CO-100-01 Datasheet →
- ES1-CO-1000 Carbon Monoxide Gas Sensor ES1-CO-1000-01 Datasheet →
- ES4-CO-100 Carbon Monoxide Gas Sensor ES4-CO-100-01 Datasheet →
- ES4-CO-1000 Carbon Monoxide Gas Sensor ES4-CO-1000-01 Datasheet →
Chlorine
Chlorine Dioxide
Ethylene Oxide
- ES1-ETO-10 Ethylene Oxide Gas Sensor ES1-ETO-10-01 Datasheet →
- ES1-ETO-1000 Ethylene Oxide Gas Sensor ES1-ETO-1000-01 Datasheet →
- ES1-ETO-200 Ethylene Oxide Gas Sensor ES1-ETO-200-01 Datasheet →
- ES4-ETO-10 Ethylene Oxide Gas Sensor ES4-ETO-10-01 Datasheet →
- ES4-ETO-1000 Ethylene Oxide Gas Sensor ES4-ETO-1000-01 Datasheet →
- ES4-ETO-200 Ethylene Oxide Gas Sensor ES4-ETO-200-01 Datasheet →
Hydrogen
- ES1-H2-1000 Hydrogen Gas Sensor ES1-H2-1000-01 Datasheet →
- ES1-H2-5% Hydrogen Gas Sensor ES1-H2-5%-01 Datasheet →
- ES1-H2-5000 Hydrogen Gas Sensor ES1-H2-5000-01 Datasheet →
- ES4-H2-1000 Hydrogen Gas Sensor ES4-H2-1000-01 Datasheet →
- ES4-H2-5% Hydrogen Gas Sensor ES4-H2-5%-01 Datasheet →
- ES4-H2-5000 Hydrogen Gas Sensor ES4-H2-5000-01 Datasheet →
Hydrogen Sulfide
- ES1-H2S-10 Hydrogen Sulfide Gas Sensor ES1-H2S-10-01 Datasheet →
- ES1-H2S-100 Hydrogen Sulfide Gas Sensor ES1-H2S-100-01 Datasheet →
- ES1-H2S-500 Hydrogen Sulfide Gas Sensor ES1-H2S-500-01 Datasheet →
- ES1-H2S-5000 Hydrogen Sulfide Gas Sensor ES1-H2S-5000-01 Datasheet →
- ES4-H2S-10 Hydrogen Sulfide Gas Sensor ES4-H2S-10-01 Datasheet →
- ES4-H2S-100 Hydrogen Sulfide Gas Sensor ES4-H2S-100-01 Datasheet →
- ES4-H2S-500 Hydrogen Sulfide Gas Sensor ES4-H2S-500-01 Datasheet →
- ES4-H2S-5000 Hydrogen Sulfide Gas Sensor ES4-H2S-5000-01 Datasheet →
Formaldehyde
Hydrogen Chloride
Hydrogen Fluoride
Ammonia
Nitrogen Dioxide
- ES1-NO2-100 Nitrogen Dioxide Gas Sensor ES1-NO2-100-01 Datasheet →
- ES1-NO2-1000 Nitrogen Dioxide Gas Sensor ES1-NO2-1000-01 Datasheet →
- ES1-NO2-2000 Nitrogen Dioxide Gas Sensor ES1-NO2-2000-01 Datasheet →
- ES1-NO2-50 Nitrogen Dioxide Gas Sensor ES1-NO2-50-01 Datasheet →
- ES4-NO2-100 Nitrogen Dioxide Gas Sensor ES4-NO2-100-01 Datasheet →
- ES4-NO2-1000 Nitrogen Dioxide Gas Sensor ES4-NO2-1000-01 Datasheet →
- ES4-NO2-2000 Nitrogen Dioxide Gas Sensor ES4-NO2-2000-01 Datasheet →
- ES4-NO2-50 Nitrogen Dioxide Gas Sensor ES4-NO2-50-01 Datasheet →
Oxygen
Ozone
Phosphine
Sulfur Dioxide
- ES1-SO2-100 Sulfur Dioxide Gas Sensor ES1-SO2-100-01 Datasheet →
- ES1-SO2-1000 Sulfur Dioxide Gas Sensor ES1-SO2-1000-01 Datasheet →
- ES1-SO2-5 Sulfur Dioxide Gas Sensor ES1-SO2-5-01 Datasheet →
- ES1-SO2-50 Sulfur Dioxide Gas Sensor ES1-SO2-50-01 Datasheet →
- ES4-SO2-100 Sulfur Dioxide Gas Sensor ES4-SO2-100-01 Datasheet →
- ES4-SO2-1000 Sulfur Dioxide Gas Sensor ES4-SO2-1000-01 Datasheet →
- ES4-SO2-50 Sulfur Dioxide Gas Sensor ES4-SO2-50-01 Datasheet →
Bare-Cell FAQs
Do I need to calibrate the bare cell myself?
Yes. A bare cell is shipped with basic testing only and no calibration data — you calibrate zero and span with standard gas at the working temperature and write it into your instrument's flash. That is the main reason a cell costs less than a module, and also why it only suits makers with calibration capability.
How do I choose between ES1, ES4 and EC4?
Decide by package and gas. ES1 (PPO, < 0.7 g) is an ultra-compact SMD for portable and space-constrained designs; ES4 (ABS, < 6 g) is a standard package for pin soldering and conventional integration; EC4 (ABS, < 8 g) is purpose-built for corrosive and halogen gases — Cl₂, F₂, HF, HCl, Br₂, ClO₂ and NH₃. When the same gas is available in both ES1 and ES4, pick ES1 for portable and ES4 for fixed.
Can a bare cell do %LEL combustible-gas alarms?
No. The EC Sense solid-polymer electrochemical bare cell is positioned for ppm-level toxic and harmful gases and is not suitable for %LEL combustible-gas alarms. For %LEL detection of methane, propane, isobutane and the like, choose Shanghai Yixin NDIR or Ningbo Xingpu low-power optical sensors — see the combustible gas sensor cluster page.
What does AG1's 'VOC/TVOC equivalent' mean?
AG1 is an 'all-gas' electrochemical sensor that responds to many volatile and toxic gases — CO, H₂, NH₃, H₂S, SO₂, NO/NO₂, O₃, PH₃ and more — factory-calibrated against CO (plus Isobutene at low range) to output an equivalent TVOC concentration. It is not a PID-style broad-spectrum ppb scan but a low-cost electrochemical alternative. If you need methane or halogenated VOCs, or ppb-level broad scanning, a PID is still the right answer.
How do I handle cross-sensitivity?
Every bare-cell datasheet carries a cross-sensitivity table listing the response to common interfering gases at a given concentration. At design time, check the table against the interfering gases actually present in your application. If cross-response is unacceptable, switch to a more selective dedicated-gas model or add a front filter. The AG1 all-gas family is a broad-response design by nature — read its cross-sensitivity table especially carefully.
What are the operating limits, lifetime and warranty?
Operating temperature -40 ℃ to +55 ℃, humidity 15 – 95% RH (non-condensing), pressure 800 – 1200 hPa, storage 0 – 20 ℃ (optimum 4 – 6 ℃). Expected lifetime is mostly > 3 years, some > 5 years; storage life 12 months; warranty 12 months; RoHS compliant.
How do I get a quote, samples and datasheets?
Every datasheet is downloadable from its product page on this site. For samples and volume pricing, send us the target gas, range, package preference and annual volume through the contact form or by email, and we will quote the matching model with lead time.
Need Help Choosing a Model?
Send us your target gas, range and package preference — we will match the model and quote it. Datasheets for all 79 bare cells are available to download now.