The Stimpmeter is an extruded aluminum bar, 36 inches long, with a V-shaped groove extending along its entire length. It has a precisely milled ball-release notch 30" from the tapered end (the end that rests on the ground). The underside of the tapered end is milled away to reduce bounce as a rolling ball makes contact with the green.
  Known as the father of the Stimpmeter, Edward S. Stimpson, left, was an accomplished golfer. (USGA Photo Archives) | |
The V-shaped groove has an included angle of 145 degrees, thereby supporting a golf ball at two points ½" apart. A ball rolling down the groove has a slight overspin, which is thoroughly consistent and has no deleterious effect on the ensuing measurments.
The ball-release notch is designed so that a ball will always be released and start to roll when the Stimpmeter is raised to an angle of approximately 20 degrees. This feature ensures that the velocity of the ball will always be the same when it reaches the tapered end.
Although the Stimpmeter is sturdily built, it is a precision instrument and should be protected from damage. When not in use, it should be stored in a plastic tube or case. Even relatively slight damage to the release notch or to the groove may cause errors.
How to Use a Stimpmeter
Equipment Required:
The ball-release notch is designed so that a ball will always be released and start to roll when the Stimpmeter is raised to an angle of approximately 20 degrees. This feature ensures that the velocity of the ball will always be the same when it reaches the tapered end.
Although the Stimpmeter is sturdily built, it is a precision instrument and should be protected from damage. When not in use, it should be stored in a plastic tube or case. Even relatively slight damage to the release notch or to the groove may cause errors.
How to Use a Stimpmeter
Equipment Required:
- Stimpmeter
- Three golf balls
- Three tees
- One 10- or 12-foot measuring tape
- One Data Sheet
Step 1 Select a level area on the green, approximately 10 feet by 10 feet. (A simple means of checking for al evel area is to lay the stimpmeter on the green and place a ball in the V-shaped groove - the movement of the ball will indicate whether or not the area is reasonably level).
Step 2 Insert a tee in the green, near the edge of the area selected, to serve as a starting point. Holding the Stimpmeter by the notched end, rest the tapered end on the ground beside the tee, and aim it in the direction you intend to roll the ball. Put the ball in the notch and slowly raise the end until the ball starts to roll down the groove. Once the ball starts to roll, Hold the Stimpmeter steady until the ball reaches the putting surface.
Repeat the same procedure with two more balls, keeping the tapered end on the same spot.
Step 3 All three balls should come to rest not more than 8 inches apart. (Should they be farther apart than that, the Stimpmeter may have moved too much during the series, the balls may be damaged or of inferior quality, or unusual conditions may exist. In any event, a pattern larger than 8 inches is of dubious accuracy, and the three-roll series should be repeated.)
Assuming the balls stop within the prescribed 8- inch limit, insert a second tee in the green at their average stopping point. The distance between the two tees is the length of the first series of rolls.
Step 4 Repeat Step 2, using the second tee as a starting point and the first tee as an aiming point. (In other words, roll a series of three balls along the same line, but in the opposite direction.)
Step 2 Insert a tee in the green, near the edge of the area selected, to serve as a starting point. Holding the Stimpmeter by the notched end, rest the tapered end on the ground beside the tee, and aim it in the direction you intend to roll the ball. Put the ball in the notch and slowly raise the end until the ball starts to roll down the groove. Once the ball starts to roll, Hold the Stimpmeter steady until the ball reaches the putting surface.
Repeat the same procedure with two more balls, keeping the tapered end on the same spot.
Step 3 All three balls should come to rest not more than 8 inches apart. (Should they be farther apart than that, the Stimpmeter may have moved too much during the series, the balls may be damaged or of inferior quality, or unusual conditions may exist. In any event, a pattern larger than 8 inches is of dubious accuracy, and the three-roll series should be repeated.)
Assuming the balls stop within the prescribed 8- inch limit, insert a second tee in the green at their average stopping point. The distance between the two tees is the length of the first series of rolls.
Step 4 Repeat Step 2, using the second tee as a starting point and the first tee as an aiming point. (In other words, roll a series of three balls along the same line, but in the opposite direction.)
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Step 5 Repeat Step 3, thereby establishing the length of the second series of rolls. Step 6 Measure the two distances - for the first series and the second series - and calculate their average. Record this as the speed of the green.
Note: Should the difference in length between the first and second series be greater than 18 inches, the accuracy of the resulting average may be questionable. The area selected for the test may not have been sufficiently level - or sufficiently representative of the green - in which case it is advisable to select another area and repeat the test. Sometimes a green may be so severely undulating or sloping that a level area is simply not available (which the data record should indicate).
Note: Should the difference in length between the first and second series be greater than 18 inches, the accuracy of the resulting average may be questionable. The area selected for the test may not have been sufficiently level - or sufficiently representative of the green - in which case it is advisable to select another area and repeat the test. Sometimes a green may be so severely undulating or sloping that a level area is simply not available (which the data record should indicate).
We measure the green speeds at St Ives Country Club three to five times a week . This is done to help the maintenance staff maintain speed uniformity through the week. There are a lot of factors that play into a stimpmeter reading, including but not limited to: height of cut, variety of grass, soil moisture content, humidity, sunlight, leaf texture, time of year, smoothness of surface, quality of turf, topdressing and rolling. Depending on any of one of these variables the speed can increase or decrease significantly. Therefore, multiple reading during the week is a must in trying to maintain consistent speeds.
We also have to find the right range of speeds that will appease the majority of the golfers. There will always be golfers who want them to roll a 14 and then you will have a set of golfers who like them at 9.5. We can't accommodate both sets so we try and keep our speeds between 11-12. When the greens are rolling in the 11-12 range we seem to keep the membership in good spirits.
Hopefully, you learned a little bit about green speeds without falling asleep! If you want to know more details on the stimpmeter or green speeds, please email me kmacdonald@valleycrest.com
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