Penetrometer Readings explained

The penetrometer reading is obtained using the following method: 

A 1 kilogram weight is released by a trigger action and falls 1 metre down a shaft, which in-turn hits a 1 centimetre square rod into the soil profile. The 1 centimetre square rod has 1 centimetre increments as the measurement for the depth the rod that has entered into the soil profile. This action is undertaken 3 times in the one position, therefore giving 3 readings eg: 2.5, 4.5, 6.5. 

A formula is used to calculate the reading and is based on the average figure for the entire course. To obtain this figure there are 6 readings taken every 200m around course. Three of the 6 readings are taken 2m from the running rail and then the remaining 3 readings are taken 4m from the running rail. Each reading is recorded and then all figures are entered into a formula that will provide an average. This average then becomes your race day penetrometer reading and will correspond to your set ratings – Good / Soft/ Heavy. Eg: Track – “Good”, Penetrometer – 4.25 cm. These readings will differ from track to track due to varying soil types and rail positions. Therefore you cannot compare readings against different tracks ie Mahalaxmi compared to Bangalore Track. Look RCTC readings, they declare it in between 1 cm to 2 cms. HRC declares PM in between 3 cm to 5.5 cm. Mysore 2 to 3 cms. DRC 1.5 to 2.3. Have you ever tried to get a clarification from the respective clubs WHY THEY ARE GIVING SUCH VARIANCE in readings.