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# siemenUnit(with:)

Returns a HealthKit unit for measuring electrical conductance, using siemen units with the provided prefix.

```
class func siemenUnit(with prefix: HKMetricPrefix) -> Self
```

## Parameters

`prefix`

A valid metric prefix value. For the complete list of prefix values, see [`HKMetricPrefix`](/documentation/HealthKit/HKMetricPrefix).

## Return Value

A HealthKit unit for measuring electrical conductance based on siemens and the provided prefix.

## Discussion

This method is used to create prefixed versions of siemens. HealthKit often records electrodermal activity in microsiemens, as shown below.

```objc
HKUnit *mcS = [HKUnit siemenUnitWithMetricPrefix:HKMetricPrefixMicro];
```

---

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