Fits all Medio-Line spring scales. The drag pointer is a plastic ring, new with well gliding Teflon components. The drag pointer easily clicks over the aluminium scale tube. Before measuring move the drag pointer towards the zero position. With increasing load the drag pointer moves down and stops at the maximum load per measurement. Suitable for rupture tests up to 1000 g. (The fine Micro-Line spring scales are not designed for use with drag pointers as possible friction might influence the reading).
Influence of Frictional Force of Drag Pointers on the Measuring Results Operating Condition of Drag Pointer -> Frictional Force
immediately after first assembly on the scale tube -> ~ 40 g / 0.4 N
one hour after assembly on the scale tube -> ~ 35 g / 0.35 N
one day after assembly on the scale tube -> ~ 28 g / 0.28 N, ever after remaining at same level
To determine the exact value of the measurement with a drag pointer, its (small) friction force on the tube will have to be deducted. Compare your operating condition with the above cited 3 versions. The indicated frictional force is to be deducted from your measuring result, except for the case of a repeated comparison measurement of no relevance to the absolute value.
HINT: Attach the new drag pointer to the tube and wait for one day until the first use. Thereafter the smallest and continuous friction force will be reached.
ATTENTION: A greasy or dirty tube surface may slightly influence the measuring result as well as bending the drag pointer ring open or compressing it (variation in friction of the drag pointer). During rupture tests the spring backstroke force may slightly displace drag pointers of very low clamping force.