diff --git a/calibration/1:2%22 pipe ring test.scad b/calibration/1:2%22 pipe ring test.scad
new file mode 100644
index 0000000..cbdea88
--- /dev/null
+++ b/calibration/1:2%22 pipe ring test.scad	
@@ -0,0 +1,23 @@
+// --- 1/2" PIPE RING TEST ARRAY ---
+$fn = 80;
+p12 = 21.3; // 1/2" Pipe OD
+wall = 3.0;
+h = 10;
+
+offsets = [0.10, 0.15, 0.20, 0.25, 0.30, 0.35];
+
+for (i = [0 : 5]) {
+    translate([i * 35, 0, 0]) {
+        difference() {
+            cylinder(d = p12 + offsets[i] + (wall*2), h = h);
+            translate([0,0,-1]) cylinder(d = p12 + offsets[i], h = h+2);
+            
+            // Identification Notches
+            for (n = [0 : i]) {
+                rotate([0, 0, n * 15]) 
+                translate([(p12 + wall*2)/2, 0, h/2]) 
+                cube([4, 1, h+1], center=true);
+            }
+        }
+    }
+}
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