> For the complete documentation index, see [llms.txt](https://docs.lorric.com/qr/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lorric.com/qr/fu-es-echosense-instruction-manual/parameters/z-easy-setup/z04-auto-zero-offset.md).

# Z04 Auto Zero Offset

### Definition

This function recalibrates the flow meter zero point (0 flow) by resetting the output to zero.\
For ultra-low flow measurements, zero calibration helps correct zero-offset errors and improves accuracy.

The function starts after pressing **Start** and automatically updates **A22 (Auto Zero Offset)** upon completion.

**Recommendation**\
It is strongly recommended to execute **Z04** when measuring flow rates below **10% of full scale**, as small zero offsets can cause significant errors at low flow.

**Example**

* Zero offset: **0.2 L/min**
  * Actual flow **100 L/min** → error ≈ **0.2%**
  * Actual flow **0.5 L/min** → error ≈ **40%**

{% hint style="info" %}
Parameter Z is not supported for Modbus read/write operations in the current version.
{% endhint %}

### Notes

1. This step **must be performed when the pipe is completely full and the liquid is fully stationary**. Running **Z04** under non-full or moving-liquid conditions may cause **flow detection errors and unstable readings**. If this occurs, repeat **Z04** under full-pipe conditions.
2. <mark style="color:red;">**Re-execute this function whenever the device is reinstalled, or when the pipe size or material changes and the flow reading is below 10% of the maximum range.**</mark>
3. **A22** has the same function as **Z04**; users may run either one.

   (**Z-series parameters** are for **quick setup during installation**, combining multiple required settings for faster configuration.)

### Operation Procedure

<details>

<summary><strong>Button Functions</strong> <em>(Click to Expand)</em></summary>

When the main screen is displayed in **green backlight**, the four buttons function as follows:

* <img src="/files/bdd75120acea6361d128fd3deec06f1a8277e667" alt="" data-size="line"> **Blue Button (leftmost):** Return, exit, or save settings.
* Gray Direction Buttons:
  * <img src="/files/2e37e572251371c6020ab6d9e11c1fcdd5ef0369" alt="" data-size="line"> **Left Gray:** Previous Page, decrease value, or select item
  * <img src="/files/50a67ff5744401e217d5b9e838da3f7909be732f" alt="" data-size="line"> **Right Gray:** Next Page, increase value, or select item
* <img src="/files/uJJ6BEZ4sukIlwQaHrUB" alt="" data-size="line"> **Orange Button (rightmost):** Rightmost button: Enter settings, edit, or confirm selection

{% hint style="danger" %}
**Do not hold buttons for extended periods to avoid damage.**
{% endhint %}

{% hint style="info" %}
Button functions may change depending on the operation context to improve usability or prevent accidental presses.
{% endhint %}

</details>

```
Z04 Automatic Zero Offset Setting Steps
• From the main screen (green backlight), 
press Orange Button (Setup) to enter settings (orange backlight).
• Use Gray Arrow Buttons to select  Z. Easy Setup , press Orange Button (Enter).
• Use Gray Arrow Buttons to select  Z04. Auto Zero Offset , press Orange Button (Enter).
• Press Right Gray Button to start Auto Zero Offset.
• Device shows “Start auto Zero Offset” when automatic zero-flow begins.
• After ~30 seconds, it displays “Set zero offset to ____”.
• Then it returns to Z04 Auto Zero Flow, indicating completion.
```

<figure><img src="/files/hGwmGKKLMEpTQFm9BTb4" alt="" width="563"><figcaption></figcaption></figure>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.lorric.com/qr/fu-es-echosense-instruction-manual/parameters/z-easy-setup/z04-auto-zero-offset.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.