> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lagerdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Thermocouple

> Read temperature from a thermocouple net

Read a temperature in degrees Celsius from a thermocouple net.

## Handle

```rust theme={null}
use lager::LagerBox;

let lager = LagerBox::from_env()?;
let tc = lager.thermocouple("tc1");
```

## Methods

| Method   | Description                             |
| -------- | --------------------------------------- |
| `name()` | The net name this handle addresses      |
| `read()` | Read the temperature in degrees Celsius |

## Method Reference

### `name() -> &str`

The net name this handle was created with.

### `read() -> Result<f64>`

Read the junction temperature in degrees Celsius.

```rust theme={null}
let celsius = tc.read()?;
println!("{celsius:.1} C");
```

**Returns:** `f64` — degrees Celsius. There is no Fahrenheit or Kelvin variant;
convert in your test if you need one.

## Examples

### Assert a part stays inside its thermal envelope under load

```rust theme={null}
use lager::{EloadMode, LagerBox};
use std::time::{Duration, Instant};

let lager = LagerBox::from_env()?;
let load = lager.eload("eload1");
let tc = lager.thermocouple("tc1");

let ambient = tc.read()?;
load.set(EloadMode::Cc, 1.5)?;

let deadline = Instant::now() + Duration::from_secs(60);
let mut peak = ambient;
while Instant::now() < deadline {
    peak = peak.max(tc.read()?);
    std::thread::sleep(Duration::from_secs(1));
}

assert!(peak - ambient < 40.0, "rose {:.1} C above ambient", peak - ambient);
```

## Supported Hardware

Any thermocouple front-end the box exposes as a `thermocouple` role net. The
amplifier and junction type are fixed when the net is created, not chosen per call.

## Notes

* Thermocouples settle slowly. A reading taken immediately after a thermal step is
  the sensor's history, not the part's temperature — sample over time.
* Cold-junction compensation happens on the instrument. The value returned is the
  compensated temperature.