> For the complete documentation index, see [llms.txt](https://docs.aethlabs.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aethlabs.com/microaethalometer-tm-ma600/manual/calibration-maintenance.md).
# 10. Calibration & Maintenance
Maintenance schedule, cleaning, flow calibration, optical calibration, and firmware update procedures for the microAethalometer™ MA600.
## 10.1 Recommended Maintenance Schedule
| Maintenance item | Frequency | Notes |
| ----------------------- | ------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Flow calibration | Annually or after service | Required after any service to pneumatic components |
| Test flow | Based on application standard operating procedure | - |
| Optical calibration | Only when instructed by AethLabs | Not a routine maintenance item |
| Air passageway cleaning | As needed or annually | AethLabs authorized service personnel only |
| Filter tape replacement | When Tape at End status appears | See [Chapter 8: On-Board Operation](https://docs.aethlabs.com/microaethalometer-tm-ma600/manual/pages/Ih2DrJl96GAEm7I3ctnc#id-8.4-filter-tape-cartridge-replacement) §8.4 |
| Firmware updates | As released | Check AethLabs website |
| Full service | Annually (or per use conditions) | AethLabs recommends annual service |
AethLabs recommends sending instruments for annual service. More frequent service may be appropriate in high-PM environments, continuous unattended operation, or after any unusual event (liquid exposure, impact, etc.).
All microAethalometer instruments are flow calibrated at approximately standard atmospheric pressure and room temperature during production. Local operating conditions vary. Before deployment, verify the flow rate at the inlet of your instrument. For sampling at higher elevations, AethLabs recommends calibrating the flow at the deployment location so that the internal mass flowmeter is calibrated for in-situ atmospheric pressure.
## 10.2 Cleaning
**External surfaces:** Clean with a dry, lint-free cloth. Do not use liquids or cleaning products.
**Air passageways and optical chamber:** Only AethLabs authorized service personnel should clean internal air passageways and optical components. Contamination degrades measurement quality, sealing, and component lifetime. If you suspect contamination of the internal optical path, contact AethLabs for service.
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**If exposed to liquids:** Immediately power off, disconnect all cables, remove all foreign substances accessible from the outside, and wait until the instrument is completely dry before turning it on again. Do not use liquids or cleaning products on the instrument.
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### 10.2.1 Preventive Maintenance for Rack Installations
The MA600 is a 3U rack-mount instrument for indoor and enclosure-based installations. For long-term installations:
* Periodically inspect the sample inlet and outlet 1/4 inch push-to-connect tubing for obstruction, kinks, or moisture.
* Verify the rack mounting screws and any support rails remain secure, especially after transport.
* Ensure adequate ventilation and clearance around the instrument so it stays within its operating temperature range.
* Keep the front and rear panels clear of dust; clean exterior surfaces with a dry cloth as needed.
* If the optional Nafion dryer is in use, verify the rear-panel **DRYER AIR IN** / **VACUUM OUT** purge connections and confirm the purge-air flow at the front needle valve ([Chapter 4: Installation](https://docs.aethlabs.com/microaethalometer-tm-ma600/manual/pages/JI7mcCGZqmB7gqPbF4B7#id-4.3-optional-nafion-dryer) §4.3).
* Monitor filter tape consumption and replace cartridges before the tape reaches its end ([Chapter 8: On-Board Operation](https://docs.aethlabs.com/microaethalometer-tm-ma600/manual/pages/Ih2DrJl96GAEm7I3ctnc#id-8.4-filter-tape-cartridge-replacement) §8.4).
## 10.3 Flow Calibration
Flow calibration requires the AethLabs MA Series Flow Calibration Kit. Third-party flowmeters are not compatible with the MA Series flow calibration process. See [Chapter 3: Getting Started](https://docs.aethlabs.com/microaethalometer-tm-ma600/manual/pages/cigM1SouxZWpVLMEYxwY#id-3.2-whats-included) §3.2 for the kit; contact AethLabs to order.
**When flow calibration is needed:**
* After any service to the pneumatic system (pump, flowmeters, tubing)
* Annually as preventive maintenance
* If the Flow Calibration Table shows results other than "OK xx/xx"
* If measured flow consistently deviates from setpoint
### 10.3.1 Prerequisites
Before starting flow calibration:
* Filter tape cartridge must be at a clean sampling location (advance tape if needed)
* Instrument connected to external 12V DC power through the "12V DC IN" M8 sealed circular connector
* MA Series Flow Calibration Kit flowmeter connected to power
* All connections sealed with no leaks
### 10.3.2 Flow Calibration Kit Setup
**Flow connections:**
* Sample inlet (1/4 inch push-to-connect) of the MA600 → outlet port of the calibration kit flowmeter
* Inlet port of the flowmeter → inline disc filter (recommended)
* Air flow direction: ambient air → inline filter → flowmeter inlet → flowmeter outlet → instrument sample inlet
**Communication connections:**
* MA Series Flow Calibration Kit communication cable → MA600 rear-panel RS-232 DB-9 **SERIAL** connection + flowmeter mini-DIN 8 port
Flowmeter settings (set automatically by the instrument during calibration)
| Setting | Value |
| ----------------------- | ------------------------- |
| Communication Baud Rate | 57600 |
| Unit ID | A |
| Gas | Air |
| Volumetric Flow Units | ml/min |
| Mass Flow Units | Sml/min (standard ml/min) |
| Flow Averaging | 255 |
| Standard Temperature | 25.00°C |
| Standard Pressure | 14.70 PSIA |
### 10.3.3 Flow Calibration Procedure
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1. Advance tape to a clean sampling location (on-board UI: 'Advance Tape').
2. Connect the instrument to external 12V DC power.
3. Connect the calibration kit communication cable to the instrument rear-panel RS-232 DB-9 serial connection and the flowmeter.
4. Connect the flowmeter outlet to the instrument sample inlet (1/4 inch push-to-connect). Verify no leaks.
5. Power on the flowmeter.
6. On the on-board UI, navigate to 'Calibrate Flow' and press center.
7. The screen displays 'FLOW CALIBRATE Switch to CAL CABLE. Press any button.'
8. Press any button to start.
9. The instrument checks flow and communications.
10. If "NO COMMS DETECTED": communications issue — check cable connections. Press any button to return to the top menu. Reconnect and retry.
11. If "NO FLOW DETECTED": flow issue — check connections, verify no leaks. Press any button to return. Reconnect and retry.
12. If communications and flow are detected, the screen displays the max achievable flow and calibration begins automatically.
13. The calibration runs multiple passes across the full flow range. This takes several minutes.
14. To cancel at any point: press the center button. The screen shows 'Flow Cal Stopping'. Press any button to return to the top menu.
15. When complete: the screen shows 'FLOWCAL - OK xx/xx Switch to REG CABLE Press any button'. Press any button.
16. Disconnect the calibration kit communication cable from the instrument.
17. Disconnect the flowmeter from the instrument inlet.
18. Verify the flow calibration table: navigate to 'Display FlowCal Info' (or use Display All Settings via terminal emulator). See §10.3.4.
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1. Advance tape to a clean sampling location (on-board UI: 'Advance Tape').
2. Connect the instrument to external 12V DC power.
3. Connect the calibration kit communication cable to the instrument rear-panel RS-232 DB-9 serial connection and the flowmeter.
4. Connect the flowmeter outlet to the instrument sample inlet (1/4 inch push-to-connect). Verify no leaks.
5. Power on the flowmeter.
6. On the on-board UI, navigate to 'Calibrate Flow' and press center.
7. The screen displays 'FLOW CALIBRATE Switch to CAL CABLE. Press any button.'
8. Press any button to start.
9. The instrument checks flow and communications.
10. If "NO COMMS DETECTED": communications issue — check cable connections. Press any button to return to the top menu. Reconnect and retry.
11. If "NO FLOW DETECTED": flow issue — check connections, verify no leaks. Press any button to return. Reconnect and retry.
12. If communications and flow are detected, the screen displays the max achievable flow and calibration begins automatically.
13. The calibration runs multiple passes across the full flow range. This takes several minutes.
14. To cancel at any point: press the center button. The screen shows 'Flow Cal Stopping'. Press any button to return to the top menu.
15. When complete: the screen shows 'FLOWCAL - OK xx/xx Switch to REG CABLE Press any button'. Press any button.
16. Disconnect the calibration kit communication cable from the instrument.
17. Disconnect the flowmeter from the instrument inlet.
18. Verify the flow calibration table: navigate to 'Display FlowCal Info' (or use Display All Settings via terminal emulator). See §10.3.4.
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### 10.3.4 Checking the Flow Calibration Table
The flow calibration table can be viewed via:
* On-board UI → 'Display FlowCal Info' (sends the table via the serial port to a terminal emulator)
* On-board UI → 'Display All Settings' (includes the full table)
**Interpreting the result:**
| Result | Meaning |
| ------------------ | -------------------------------------------------------------- |
| OK xx/xx | Calibration complete; all setpoints calibrated successfully |
| WARNING xx/xx | Calibration complete with warnings; review rows marked with \* |
| FAIL MIN xx/xx | Failed to reach minimum flow rate |
| FAIL MAX xx/xx | Failed to reach maximum flow rate |
| FAIL MIN MAX xx/xx | Failed to reach both minimum and maximum flow |
If multiple calibration attempts result in WARNING or FAIL, contact AethLabs.
### 10.3.5 Test Flow Procedure
The Test Flow feature allows checking the current internal flow reading against an external reference without performing a full calibration.
1. Connect an external reference flowmeter to the instrument sample inlet. Use the AethLabs MA Series Flow Calibration Kit flowmeter or a low-backpressure (low-pressure-drop) flowmeter as the external reference — a low-backpressure meter is required so it does not restrict the sample flow.
2. Navigate to 'Test Flow' in the on-board UI menu.
3. Use the left/right buttons to select the desired target flow within the MA600 flow range of 100–250 ml/min.
4. The screen displays the current target and measured flow.
5. Allow a few seconds for the pump speed to stabilize.
6. Compare the displayed measured flow against the external flowmeter reading.
7. Press center to exit.
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To test in DualSpot® or SingleSpot™ mode, the sampling mode must first be set in microAeth® Manager before using the Test Flow feature.
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## 10.4 Optical Calibration
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**OPTICAL CALIBRATIONS ARE NOT RECOMMENDED UNLESS INSTRUCTED BY AETHLABS OR AETHLABS AUTHORIZED SERVICE PERSONNEL.**
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Optical calibration adjusts the internal reference values for the optical measurement system. It is a service-level procedure, not a routine maintenance step.
**Prerequisites:**
* Filter tape at a clean sampling location
* Instrument connected to external 12V DC power
* Cartridge door installed and closed
* Note: Optical calibration **cannot be cancelled** once started
**Procedure:**
1. Advance tape to a clean location if needed.
2. Connect the instrument to external 12V DC power through the "12V DC IN" M8 connector.
3. Verify the cartridge door is installed and closed.
4. Navigate to 'Calibrate Optics' in the on-board UI.
5. Press center to enter the submenu. 'YES OK NO' is displayed.
6. Use the left button to select YES, the right button to select NO.
7. Press center to confirm the YES or NO selection.
8. If YES is confirmed, optical calibration starts. 'Starting' is displayed.
9. The screen shows 'Calibrating... xxxx' as progress updates.
10. When complete, 'Calibration Complete' is displayed and the menu returns to the top level automatically.
## 10.5 Firmware Updates
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**IMPORTANT:** Download and back up all data from the instrument before any firmware update. Data may not be accessible after a firmware upgrade.
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**BEFORE PROCEEDING:** If upgrading from firmware v1.09 or earlier, contact AethLabs support first.
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### 10.5.1 Firmware Update via microAeth Manager (Recommended)
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1. Verify microAeth Manager version is 1.8 or newer (check via Manage application → Info).
2. Download the latest firmware from the AethLabs website if not already available.
3. Connect the instrument via the AethLabs Serial DB-9 to USB Converter Cable (not the regular USB cable for this procedure).
4. In microAeth Manager, click 'Firmware updates' (top right of main window).
5. Follow the on-screen instructions in order — each step must show a checkmark before proceeding.
6. Turn off the instrument when prompted.
7. Use the 'Select a serial port' dropdown to select the correct COM port connected to the converter cable.
8. Click 'Select firmware file' and locate the `.hex` firmware file.
9. Power on the instrument in bootloader mode: **press and hold left + right buttons simultaneously for 3 seconds** until the LCD backlight flashes three times, then release.
10. When the application advances, press center button on the instrument to start the file transfer.
11. The application displays transfer progress.
12. If upgrade fails: the application shows 'X' marks. Click 'Again' to retry.
13. On success: 'Firmware update successful' is displayed. Click 'Close' or 'Again' for another unit.
14. After upgrade: verify the flow calibration table (§10.3.4) and configure all settings via microAeth Manager.
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1. Verify microAeth Manager version is 1.8 or newer (check via Manage application → Info).
2. Download the latest firmware from the AethLabs website if not already available.
3. Connect the instrument via the AethLabs Serial DB-9 to USB Converter Cable (not the regular USB cable for this procedure).
4. In microAeth Manager, click 'Firmware updates' (top right of main window).
5. Follow the on-screen instructions in order — each step must show a checkmark before proceeding.
6. Turn off the instrument when prompted.
7. Use the 'Select a serial port' dropdown to select the correct COM port connected to the converter cable.
8. Click 'Select firmware file' and locate the `.hex` firmware file.
9. Power on the instrument in bootloader mode: **press and hold left + right buttons simultaneously for 3 seconds** until the LCD backlight flashes three times, then release.
10. When the application advances, press center button on the instrument to start the file transfer.
11. The application displays transfer progress.
12. If upgrade fails: the application shows 'X' marks. Click 'Again' to retry.
13. On success: 'Firmware update successful' is displayed. Click 'Close' or 'Again' for another unit.
14. After upgrade: verify the flow calibration table (§10.3.4) and configure all settings via microAeth Manager.
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### 10.5.2 Firmware Update via Tera Term (Windows Only, Advanced)
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IT IS HIGHLY RECOMMENDED TO USE microAeth Manager FOR FIRMWARE UPDATES (SEE §10.5.1). USE THIS METHOD ONLY IF microAeth Manager IS NOT AVAILABLE.
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AethLabs supports only Tera Term for Windows for this method. CoolTerm and other terminal emulators are not supported for firmware updates.
**Terminal settings:**
| Setting | Value |
| ------------ | --------- |
| Baud Rate | 1,000,000 |
| Data | 8 bit |
| Parity | None |
| Stop | 1 bit |
| Flow control | Xon/Xoff |
**Procedure:**
1. Unplug the instrument from all external power.
2. Connect the computer to the instrument's rear-panel RS-232 DB-9 **SERIAL** port (via a DB-9 serial port or a USB-to-serial adapter).
3. Open Tera Term. In the 'New connection' dialog, select Serial and choose the correct COM port.
4. Set the serial port settings as above via Setup → Serial port.
5. Navigate to 'Turn off' in the on-board UI menu and power off the instrument.
6. With the instrument off, **press and hold left + right buttons simultaneously for 3 seconds** to enter the bootloader.
7. If successful, the screen backlight flashes three times and stays on, and the terminal displays bootloader version information. If unsuccessful, the instrument turns off and nothing is displayed — ensure the instrument is off and retry.
8. The bootloader displays: 'Press CENTER button to start bootload process, Press LEFT or RIGHT to CANCEL.' You have 30 seconds to make a selection before automatic timeout. Press center to start the bootloader upgrade.
9. The terminal displays: 'Waiting for download... (you have 30s).' In Tera Term, go to File → Send file. Select the firmware `.hex` file. Press Open.
10. Transfer begins immediately. `*` symbols appear as progress. Do not interrupt.
11. On success: 'GOOD LOAD', 'SUCCESS', 'Shut Down' are displayed and the instrument powers off. On failure: 'BAD LOAD' is displayed — the instrument has no valid firmware and only the bootloader will start on power-on. Retry the process.
12. After a successful upgrade: turn on the instrument, verify the flow calibration table (§10.3.4), and configure all settings via [microAeth Manager](/microaethalometer-tm-ma600/manual/mam-software.md).