Step 1: MultiRAE Lite - Device Navigation and Setup
Before beginning, ensure all sensors are active and displaying some form of reading on the home screen—this confirms they are ready for calibration [00:44].
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Entering Calibration Mode: Press and hold the power button and the right-hand button simultaneously to bring up the main programming menu [00:20].
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Menu Selection: Use the buttons on the bottom of the device to select the "Calibration" menu, where you can modify span values or choose specific sensor tests [01:10].
Step 2: Gas Cylinder and Span Verification
To ensure an accurate calibration, you must verify that the target parts per million (ppm) values programmed into the device exactly match the concentrations listed on your physical calibration cylinders [01:44].
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Standard 4-Gas Cylinder: Program the device to match the 4-gas mix concentrations: 50% LEL (methane), 18% Oxygen, 25 ppm Hydrogen Sulfide, and 100 ppm Carbon Monoxide [02:33].
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VOC Cylinder: Because Volatile Organic Compounds (VOCs) require a separate gas, verify the standalone target value is set to 100 ppm Isobutylene [02:53].
Step 3: Calibration Execution (Fresh Air and Multi-Sensor)
The calibration process requires a strict flow order to protect the integrity of the sensors:
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Fresh Air Calibration: This process must be started manually. Select the fresh air option and take the monitor outside into clean air for its 1-minute zeroing cycle [03:31].
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Multi-Sensor Span: Attach the regulator and calibration cap to the top of the 5-gas meter to deliver the 4-gas mix [03:59].
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Pro Tip: Always run your regulator at exactly 0.5 Liters per minute [04:14]. Crucially, do not press the manual start button on the screen. Let the gas flow and allow the sensors to automatically detect it and start the timer on their own—this confirms the sensors are healthy and functioning [04:22].
Step 4: VOC Sensor Calibration
The monitor handles its five gases sequentially to prevent cross-contamination of the sensor chambers:
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Automated Prompts: The multi-calibration ecosystem is highly intuitive; as soon as the 4-gas mixture passes, the unit automatically prompts you to begin the separate VOC calibration [05:06].
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Gas Application: Just like the previous step, do not force a manual start. Turn on your Isobutylene cylinder and let the PID sensor automatically trigger its own reading [05:13].
Step 5: Post-Calibration Diagnostics
Once the calibration cycles are complete, you should run a quick field diagnostic before deploying the unit:
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Clearing Residual Gas: It is entirely normal for gas readings to linger on the home screen right after pulling off the calibration cap [05:58]. If you want them to clear out to baseline zeros quickly, simply expose the device to fresh air again [06:11].
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The Functional "Bump" Check: To test response speed and real-world accuracy, crack open your gas regulator and hold the open tubing near the unit without the calibration cap to ensure it rapidly registers the gas profile.
