# Sample and Specimen Model

The **Sample Data** section holds every sample associated with a location. Each sample carries a reference, a depth interval, and the sampling metadata that links it back to the field operation; specimens (subsamples) reference their parent sample for hierarchical tracking.

For the related concepts, see also:

* [Borehole and Location Model](/concepts/borehole-and-location-model.md) — the location these samples belong to.
* [Layer and Stratigraphy](/concepts/layer-and-stratigraphy.md) — ground descriptions at the depths these samples cover.

## Sample fields

Each sample has:

* **Sample reference** — sample name, often just a number; user-defined and advised to be unique within a location.
* **Recovery from / to depth** and **penetration from / to depth**.
* **Sample condition** — disturbed / undisturbed / etc., from a dictionary.
* **Sampling method** — grab sample, auger, etc., from a dictionary.
* **Sample type** — bag, etc., from a dictionary.
* **Date, comments, blow count.**

{% hint style="info" %}
**Sample condition for specific tests** (e.g. undisturbed / remoulded on a UU triaxial test) is stored inside the *test parameters*, not directly on the sample record. The sample-record condition refers to the sample as collected; per-test conditions vary across the laboratory program.
{% endhint %}

## Parent samples and specimens

Subsamples and specimens reference their parent sample via the `Parent Sample Reference` column. This produces a clean parent-child structure in the sample table: a single parent (e.g. a 4-inch liner tube) with multiple specimens taken from it for individual lab tests.

## Onsite sample workflow

In GeoDin Onsite, the sample workflow on a drilling form is:

1. Select **sampling method** (e.g. liner tube, 4-inch).
2. Select **condition** (e.g. undisturbed).
3. Enter **recovery percentage** (e.g. 95 %+).
4. Select **sample type**.
5. Set **depth reference**.
6. Print a **QR-coded label** that can be stuck on the physical sample.

## Onsite sample IDs

Onsite assigns each soil sample a unique ID with a fixed structure:

| Component        | Length            | Notes                                                                   |
| ---------------- | ----------------- | ----------------------------------------------------------------------- |
| Prefix letter(s) | 1–3 chars         | Configurable                                                            |
| Timestamp        | 6 chars           | Encodes the moment of sampling                                          |
| Random           | 4 chars (default) | Shrinks if prefix grows so that *prefix + random* always totals 5 chars |

The timestamp portion changes every second, so collisions only happen if more than \~20–100 samples are generated in the exact same second.


---

# Agent Instructions: 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:

```
GET https://docs.geodin.com/concepts/sample-and-specimen-model.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.