250 cc Model (RIP2)
- Dig snow pit wall or surface to be sampled. Shave the wall or surface with a flat-bladed shovel to give a smooth sampling surface. Surface must not be rough or sampling error will result. Position cutter perpendicular to surface in both vertical and horizontal directions.
- Insert cutter at desired location. Be sure to insert cutter perpendicular to the surface so that the entire back of the cutter is flush with the snow surface when the cutter is all the way in. Do not attempt to straighten cutter after it is partially inserted or sampling error will result. It is better to move cutter and resample correctly. Do not push cutter in farther than snow surface or over sampling will occur.
- Place lid adjacent to top edge of cutter at an angle close to the angle of the upper cutter surface.
- Hold cutter in place with one hand while inserting cutter lid in with the other. Do not allow cutter to slide back as lid is pressed in as undersampling will occur.
- In consolidated or wet snow, once the lid is pressed in and the sample has been isolated, the cutter and sample may be removed and weighted while the lid is left in. In new, unconsolidated, weak, or kinetic (depth hoar) snow, the lid should be removed from the pit wall with the cutter to insure no sample loss.
- Transfer the snow sample to the plastic baggie hanging from your spring scale. The weight in grams is simply multiplied by 4 to get density in kilograms per meter cubed (kg m -3), because the sample size is 250 cc. For example: a weight in grams of 90 gives 90 x 4 = 360 kg m-3. Percent density is calculated by dividing the number above by 1000 (36%). If you are using a digital top-loading scale, the lid is removed after the sample is turned upright, and the sample (still in the cutter) is placed directly on the scale.
Best results are obtained by inserting the flat bottom of the cutter vertically into the snowpack because this insures that heterogeneous layers are sampled evenly by the wedge shaped cutter. Hold the cutter handle in your left hand as you would a key being inserted into a lock; and hold the lid in your right hand. Reverse this procedure if you are left handed. Since the lid perturbs the snow above and below the cutter, a continuous density should be sampled by staggering alternate samples to one side or the other.
In extremely dense snow, refrozen melt-freeze or thick ice lenses it may be tempting to beat on the cutter or lid. Don't do it! If you are sampling this type of snow, consider our 1000 cc cutter which is designed to handle that kind of abuse. In conditions where sticking or icing make sample removal difficult, a putty knife may be helpful. Use it to scrape the cutter clean after the sample has been weighed, if weighing in the cutter, or use it to scrape entire sample into weighing baggy if a spring scale is used. The lid cutter also works well for this purpose. If you have any questions, suggestions, or problems concerning sampling snow density in general or this sampler in particular, please fee free to call, write or e-mail.