Document minimum delay constraints for sweep operations

README.md

@@ -164,6 +164,35 @@ sweep.start()
   the notebook cell output, so database switches and sweep transitions are
   visible while the queue runs.
 
+## Sweep Timing Constraints
+
+MeasureIt enforces minimum delay values to ensure thread-safe operation and reliable measurement timing:
+
+| Parameter | Minimum Value | Applies To | Description |
+|-----------|--------------|------------|-------------|
+| `inter_delay` | **0.01s** (10ms) | All sweeps (Sweep1D, Sweep2D inner) | Time between measurement points |
+| `outer_delay` | **0.1s** (100ms) | Sweep2D outer sweep | Time between outer sweep lines |
+
+**Why These Minimums?**
+- These minimums ensure reliable data collection and prevent measurement timing issues
+- They protect the runner thread timing and ensure stable communication between measurement threads
+- Values below these minimums will raise a `ValueError` with a descriptive error message
+- The defaults (`inter_delay=0.1s`, `outer_delay=1.0s`) are safe for most use cases
+
+**Example:**
+```python
+# Valid sweep with minimum delays
+sweep2d = measureit.Sweep2D(
+    in_params=[inner_param, 0, 1, 0.01],
+    out_params=[outer_param, 0, 10, 0.1],
+    inter_delay=0.01,  # Minimum allowed
+    outer_delay=0.1     # Minimum allowed
+)
+
+# This would raise ValueError: inter_delay too small
+# sweep2d = measureit.Sweep2D(..., inter_delay=0.005)  # < 0.01s ❌
+```
+
 ## Documentation
 
 ### Building Documentation

src/measureit/sweep/base_sweep.py

@@ -42,7 +42,8 @@ class BaseSweep(QObject):
     set_param:
         QCoDeS Parameter to be swept, defaults to None for 0D sweep.
     inter_delay:
-        Time (in seconds) to wait between data points.
+        Time (in seconds) to wait between data points. Must be >= 0.01s.
+        Default: 0.1s
     save_data:
         Flag used to determine if the data should be saved or not.
     plot_data:
@@ -149,7 +150,8 @@ def __init__(
         set_param:
             QCoDeS Parameter to be swept, defaults to None for 0D sweep.
         inter_delay:
-            Time (in seconds) to wait between data points.
+            Time (in seconds) to wait between data points. Must be >= 0.01s.
+            Default: 0.1s
         save_data:
             Flag used to determine if the data should be saved or not.
         plot_data:

src/measureit/sweep/sweep2d.py

@@ -25,9 +25,11 @@ class Sweep2D(BaseSweep, QObject):
     out_params:
         List defining the outer sweep [parameter, start, stop, step].
     inter_delay:
-        Time (in seconds) to wait between data points on inner sweep.
+        Time (in seconds) to wait between data points on inner sweep. Must be >= 0.01s.
+        Default: 0.1s
     outer_delay:
-        Time (in seconds) to wait between data points on outer sweep.
+        Time (in seconds) to wait between data points on outer sweep. Must be >= 0.1s.
+        Default: 1.0s
     save_data:
         Flag used to determine if the data should be saved or not.
     plot_data:
@@ -116,9 +118,11 @@ def __init__(
         out_params:
             A list conforming to above standard for the outer sweep.
         inter_delay:
-            Time (in seconds) to wait between data points on inner sweep.
+            Time (in seconds) to wait between data points on inner sweep. Must be >= 0.01s.
+            Default: 0.1s
         outer_delay:
-            Time (in seconds) to wait between data points on outer sweep.
+            Time (in seconds) to wait between data points on outer sweep. Must be >= 0.1s.
+            Default: 1.0s
         save_data:
             Flag used to determine if the data should be saved or not.
         plot_data: