These high quality stainless steel sample loops have burr-free, square-cut ends to ensure a flush connection to valve ports. The size designations of loops are nominal. The actual volumes can differ from the theoretical designations because of the 0.001" (± 0.025 mm) tolerance of the metal tubing bore.
Accuracy of large metal loops (1.0 mm, 0.040" bore) is about ±5%, intermediate loops (0.5 mm, 0.020" bore) ±10%, and small loops (0.2 mm, 0.007" bore) ±30%.
Since both standards and unknowns are usually analyzed using the same sample loop, knowledge of the actual, accurate volume is rarely needed. If the sample loop volume must be known, it is best to calibrate the loop in place on the valve so the flow passages in the valve are also taken into account. An alternative to calibration is to use a dual mode injector and partial-filling method of loading. See the "Sample Loop Loading" Application Note.
Model 7725 Injector loops are not interchangeable with loops for the model 7125. The port angle for the 7725 is 30° whereas the port angle for the 7125 is 20° requiring the loops to have a different shape.
Model 8125 Micro-Scale Sample Injector requires special loops in the 5.0 µL to 50 µL range. The 8125 sample loops are made with 0.5 mm (0.020") OD tubing.
