SemeaTech electrochemical gas sensors for ETO, CO, H2S, O2 and PID sensors

SemeaTech 4, 7, 3 and mini-Series electrochemical sensors for ethylene oxide, carbon monoxide, hydrogen sulfide and oxygen, plus PID photoionization sensors. Selection by series, gas and range, quotation per project.

ETO ethylene oxide sensors: calibration and replacement

Electrochemical ethylene oxide sensors 4-Series ETO-10, ETO-100, ETO-500 and 7-Series ETO-20, ETO-100. ETO-10 covers 0–10 ppm with 0.05 ppm resolution, T90 response of 120 s or less and +300 mV bias. It is a pin-to-pin replacement for a standard 4-series ETO cell.

ETO-10 range: 0–10 ppm
Resolution 0.05 ppm
T90 response ≤ 120 s
Bias voltage +300 mV

CO carbon monoxide sensors: cell replacement

The 4-Series CO line runs from CO-50 to CO-20000. CO-2000 covers 0–2,000 ppm with overload up to 5,000 ppm, T90 response of 30 s or less and an expected operating life of 2 years in clean air. It replaces a standard 4-series CO cell.

CO-2000 range: 0–2,000 ppm
Overload up to 5,000 ppm
T90 response ≤ 30 s
Operating life 2 years

H2S hydrogen sulfide sensors: selection and replacement

4-Series H2S sensors cover several ranges, from H2S-10 to H2S-1000 and above. H2S-10 measures 0–10 ppm, H2S-100 measures 0–100 ppm with overload up to 500 ppm. H2S-100HT is the high temperature resistant version, H2S-100A is interference resistant.

H2S-10 range: 0–10 ppm
H2S-100 range: 0–100 ppm
HT suffix: high temperature
A suffix: interference resistant

O2-LF oxygen sensors: testing and replacement

Lead free oxygen sensors 4-Series O2-LF, O2-LF-M and O2-LF-100%. O2-LF covers 0–25% vol oxygen with T90 response of 15 s or less, −600 mV bias and an expected operating life of 5 years in clean air. It replaces a standard 4-series oxygen cell.

Range 0–25% vol oxygen
T90 response ≤ 15 s
Bias voltage −600 mV
Operating life 5 years

7-Series sensors: replacement in fixed systems

7-Series sensors are designed for outdoor fixed gas monitoring systems with long-term operation. The line includes CO-50…CO-10000, H2S-50…H2S-10000, ETO-20 and ETO-100. 7-Series ETO-100 covers 0–100 ppm with 0.5 ppm resolution and overload up to 500 ppm.

Fixed gas monitoring systems
Models CO-50…CO-10000
Models H2S-50…H2S-10000
ETO-100 range: 0–100 ppm

3-Series sensors for flue gas: replacement

3-Series sensors are slightly larger than the 4-series and are used for flue gas analysis and stack emission monitoring. The line has carbon monoxide models CO-2000 to CO-20000, sulfur dioxide SO2-500 and SO2-2000, nitrogen dioxide NO2-500 and nitric oxide NO-2000.

Flue gas analysis
Models CO-2000…CO-20000
Models SO2-500 and SO2-2000
Models NO2-500 and NO-2000

mini-Series sensors for portable detectors: replacement

mini-Series sensors are designed for compact detectors, personal protection and portable safety devices. The line includes CO-1000S, ETO-100, HCN-10S, CL2-20 as well as phosphine PH3-20A and arsine AsH3-10 sensors. Replacement is matched by gas and suffix.

Portable safety devices
Models CO-1000S and ETO-100
Hydrogen cyanide HCN-10S
Phosphine PH3-20A, arsine AsH3-10

PID photoionization sensors: testing and replacement

SemeaTech makes 4-Series and 7-Series PID sensors in collaboration with Senovol. Lamp photon energy is 10.6 eV and the range is 0–10,000 ppm isobutylene. T90 response is 5 s or less for the 4-series and under 10 s for the 7-series. Lamps come in 1/4, 3/8 and 1/2 inch sizes.

Photon energy 10.6 eV
Range 0–10,000 ppm
T90 ≤ 5 s on 4-series
Lamps 1/4, 3/8, 1/2 inch

How to select a SemeaTech sensor

Selection starts with the instrument platform: the 4-series is compact and lightweight for portable gas monitors; the 7-series is for fixed gas monitoring systems; the 3-series is for flue gas analysis and stack emission monitoring; mini is for compact detectors and personal protection devices.

Next, the gas and range are chosen from the sensor name (for example, 4-Series ETO-10 is ethylene oxide, 0–10 ppm) and the conditions are checked: ETO-10 operates from −20 to 50 °C.

SemeaTech platforms and technologies

Most of the range is electrochemical sensors for CO, H2S, O2, ETO, SO2, NO, NO2, NH3, Cl2, HCN and other gases. For volatile organic compounds SemeaTech makes PID photoionization sensors in collaboration with Senovol: the 7-series with a larger lamp is intended for a life of two years or more.

The range also includes NDIR infrared sensors, LEL pellistor sensors and modules with I2C and UART digital outputs.

Suffixes in the sensor name

The letter suffix after the range sets the version: A interference resistant, B dry and humidity resistant, F with H2S filter, HT high temperature, L long life, LF lead free, S fast response, U unbiased. Bias voltage depends on the gas: +300 mV for ETO-10, −600 mV for O2-LF.

Calibration with reactive gases

For Cl2, ClO2, NH3, O3, NO2, HCN, HF and HCl the maker gives a separate procedure: PTFE tubing as short as possible, a stainless steel regulator for each gas, 0.3–1.0 LPM flow and a PTFE or stainless steel calibration cap.

The system is first balanced with a higher concentration, which may take 30 minutes or longer.

The company SemeaTech

SemeaTech was founded in Los Angeles and Shanghai. The Los Angeles branch focuses on basic research, the Shanghai branch on product development and volume production. Series, gas, range and quantity are stated in the quotation for each project.

SemeaTech and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of SemeaTech and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.