TB200B Industrial Safety Gas Sensor Modules

Selection Guide

Five Steps to the Right Model

The TB200B spans 23 gas types and 136 models, and most gases come in several ranges with two cell options and two interfaces. Work through the sequence below and the choice usually narrows to one or two models.

1. Step 1 — Identify the target gas and the background gases

   Decide what you are measuring, then what else is present on site. Background gases drive interference risk — and decide whether a different principle is needed: if you are measuring VOCs alongside high CO or NO₂, metal-oxide approaches are largely ruled out. Our electrochemical sensors optimise electrode chemistry and bias per target gas, and cross-sensitivity data is published in each model's datasheet for checking item by item.

2. Step 2 — Size the range from your alarm setpoint

   The usual mistake is buying the widest range available — a wider range means coarser resolution. A practical rule: pick a range two to five times your alarm setpoint. For H₂S, where occupational limits sit around 10 ppm, a 0 – 100 ppm model is enough; you do not need 0 – 5000 ppm. Every range for every gas appears in the matrix below, with resolution down to 0.001 ppm.

3. Step 3 — Choose the cell: ES1, ES4 or EC4

   This is the step that sets module height and service life. The ES1 version is 12 mm tall overall and weighs under 15 g; the ES4 version is 22.45 mm tall and under 25 g. Both use solid-polymer electrochemistry with an expected lifetime beyond 5 years and 1% repeatability. The EC4 version is also 22.45 mm tall but uses liquid electrochemistry, aimed specifically at corrosive gases such as bromine, fluorine, hydrogen chloride and hydrogen fluoride, with an expected lifetime beyond 2 years and 2% repeatability. Chlorine, chlorine dioxide, ammonia and ozone are offered in both ES1/ES4 and EC4 versions, so you can trade off site concentration against replacement interval.

4. Step 4 — Pick the interface: UART or I²C

   The same gas and range normally come in both a UART and an I²C order number; only the communication method and pinout differ. The UART version runs 9600 bps, 8 data bits, 1 stop bit, on four wires: VCC (red), GND (black), RX (yellow), TX (green). The I²C version runs at up to 20 kHz with 3.3 V signalling on VCC (red), GND (black), SDA (yellow), SCL (green). I²C suits several modules on one bus provided addresses are planned; UART point-to-point is simpler for one or a few heads.

5. Step 5 — Check supply, fit, environment and compliance

   Supply is 3.3 – 5.5 V DC (5 V recommended) with under 5 mA working current and 40 mW at 5 V; peak current is 3.8 mA for the UART version and 6.2 mA for I²C, with 0.8 / 0.9 mA in sleep. The board itself measures 40 × 30 × 5.6 mm without the sensor and ships with a 100 mm four-pin cable. Confirm the site stays within -40 °C to +55 °C, 15 – 95% RH non-condensing and atmospheric pressure ±10%, and whether your project needs RoHS or similar documents — certification status is stated in each model's datasheet, and we can supply the reports we hold. Warranty is 12 months from the date of shipment.

TB200B or TB600B&C — Which One?

Both series are EC Sense solid-polymer electrochemical modules, both report gas plus temperature and humidity, and both use the same four-wire colour code. Two practical questions decide it: do you need a smaller board, and will the site involve gases such as oxygen, halogens or hydrogen halides?

Both series report concentration directly, so the choice comes down to board size, power budget and the gas list. If you are unsure, send us the application — we will tell you which series fits, including when neither does and a different principle is the better answer (for %LEL alarms, for instance, catalytic bead or infrared).

Frequently Asked Questions