--- title: Smart ESM Turbidity Onboard Calibration Check Procedure description: ESM turbidity calibration, Turbidity on board check calibration procedure --- [Skip to content](https://hub.rivertrace.com/knowledge/smart-esm-turbidity-onboard-calibration-check-procedure#main-content) English Show submenu for translations [Submit a request](https://hub.rivertrace.com/knowledge/kb-tickets/new) [![Rivertrace-Logo-Blue-on-White](https://hub.rivertrace.com/hs-fs/hubfs/Rivertrace%20Logos/Rivertrace-Logo-Blue-on-White.jpg?width=412&height=150&name=Rivertrace-Logo-Blue-on-White.jpg)](https://www.rivertrace.com) Open main navigation Close main navigation - English Show submenu for translations - [Submit a request](https://hub.rivertrace.com/knowledge/kb-tickets/new) - [Cant find what you need? Contact our remote support team.](mailto:remotesupport@rivertrace.com) [Cant find what you need? Contact our remote support team.](mailto:remotesupport@rivertrace.com) How can we help you? - There are no suggestions because the search field is empty. 1. [Knowledge Base](https://hub.rivertrace.com/knowledge) 2. [Smart ESM](https://hub.rivertrace.com/knowledge/smart-esm) # Smart ESM Turbidity Onboard Calibration Check Procedure ## Step-by-step guide for performing onboard turbidity calibration checks **Spare parts required:** > Turbidity solutions Kit             (Part Numbers **112385)** Protective gloves and safety glasses should be worn when carrying out this procedure. **Procedure:** **Step 1**: At the filter isolate both valves\* so that there is no flow through the filters. Switch the motor  isolation switch off. \*Depending on the version of your system, selected motor and pipework, your layout may  vary – example layouts below with isolation valves circled in RED. If in doubt, please contact:   remotesupport@rivertrace.com. ![](https://hub.rivertrace.com/hs-fs/hubfs/image-png-Jan-27-2026-11-49-23-0223-AM.png?width=670&height=443&name=image-png-Jan-27-2026-11-49-23-0223-AM.png)   ![](https://hub.rivertrace.com/hs-fs/hubfs/image-png-Jan-27-2026-11-50-29-7677-AM.png?width=505&height=313&name=image-png-Jan-27-2026-11-50-29-7677-AM.png) **Step 2:**  Shake the  bottles of fluid for 1 minute to obtain uniformity and then leave to stand for 5 minutes to release any air bubbles. **Step 3:**  Press and hold the Clean button on the touchscreen and follow the instructions shown on the screen. This will force the ESM into clean water mode and flush the cell with clean water. After 3 minutes press the abort button to stop the clean water flow.  **Step 4:**  Drain the cell by opening the drain valves at the inlet and outlet to the cell, allow to drain then close the valves.  ![](https://hub.rivertrace.com/hs-fs/hubfs/image-png-Jan-27-2026-11-57-49-3512-AM.png?width=670&height=165&name=image-png-Jan-27-2026-11-57-49-3512-AM.png)   **Step 5**: At the air regulator decrease the pressure to Zero.  **Step 6**: Remove the 2 plastic pipes that are connected to the top and bottom of the autoclean ( recording which pipe fits with port on the autoclean cylinder) then remove the autoclean by unscrewing the plastic cap  **Step 7**: Using the syringe pour 120mL of the following NTU solutions into the autoclean port on the top of the cell. Draining and flushing the cell each time a new concentration is poured into the cell **Step 8**: Observe and record the turbidity reading on the screen. ``` 0 NTU -----> Must display O NTU 50NTU -----> Must display between 49 and 51 350NTU -----> Must display between 349 and 351 ``` **Step 9**: Drain the solution and refit the autoclean plunger to the cell **Step 10**: Refit the 2 plastic pipes to the autoclean.  **Step 11**: De-isolate the valves on the filter and change the pump isolator switch to on. **Step 12**: A calibration check certificate can be created on our RT connected  calibration Portal and send to the customer.   ``     - [Smart ODME](https://hub.rivertrace.com/knowledge/smart-odme) - [SmartBilge](https://hub.rivertrace.com/knowledge/smartbilge) - [Smart Bilge+ Plus](https://hub.rivertrace.com/knowledge/smart-bilge-plus) - [Smart PFM](https://hub.rivertrace.com/knowledge/smart-pfm) - [OCD CW](https://hub.rivertrace.com/knowledge/ocd-cw) - [Smart ESM](https://hub.rivertrace.com/knowledge/smart-esm) - [OCD Xtra](https://hub.rivertrace.com/knowledge/ocd-xtra) - [Smart 50M](https://hub.rivertrace.com/knowledge/smart-50m) - [Smart Turbidity](https://hub.rivertrace.com/knowledge/smart-turbidity) - [Sample conditions and general techniques](https://hub.rivertrace.com/knowledge/sample-conditions-and-general-techniques) - [General FAQs](https://hub.rivertrace.com/knowledge/general-faqs) - [Key MEPC Regulations and Rivertrace Solutions](https://hub.rivertrace.com/knowledge/key-mepc-regulations-and-rivertrace-solutions) - [OCD CM](https://hub.rivertrace.com/knowledge/ocd-cm) [![Rivertrace-Logo-Black](https://hub.rivertrace.com/hs-fs/hubfs/Rivertrace%20Logos/Rivertrace-Logo-Black.jpg?width=271&height=99&name=Rivertrace-Logo-Black.jpg "Rivertrace-Logo-Black")](https://www.rivertrace.com) Rivertrace Product, Regulation and Technical Support Knowledge Base Copyright © 2025, Rivertrace Limited