Cleaning Your Equipment - Thermo Scientific NITON XL3t 500 User Manual

Preparing Bulk Soil
Cleaning Your
Equipment:
Sample Preparation
Thermo Scientific
5. Brush the finely grounded samples into 31 mm aluminum sample
cap and press at 50,000psi for 1 min.
We recommends establishing a specific sample protocol. Following this
protocol for preparing and testing samples is vital for achieving a level of
Samples
accuracy comparable with laboratory results.
The equipment you need to prepare samples is included in your kit. Among
these are a mortar and pestle, several different sized metal sieves, cups to
hold the samples, and the soil test platform.
CAUTION All test equipment must be kept clean to prevent contamination
of samples.
The mortar, pestle, and grinding mill may be cleaned with dry paper towels.
You can also clean the mortar, pestle, and the mill's container with water,
but be sure each is absolutely dry before using them on another sample. The
mortar and pestle may be cleaned by grinding clean, dry sand in the mortar.
Use the short bristle brushes (included in your Soil Testing Kit) to clean the
sieves. If you have an electric soil grinder in your kit, when the soil grinder
blades wear out, unbolt the worn blades and replace them. Call the Thermo
Sales Department at 1-800-875-1578 for replacement blades.
Note Using the soil grinder may artificially increase the amount of Fe in soil
samples.
Prior to analysis, the material should be dry and well homogenized. Ideally,
the entire sample should be dried to constant weight, sifted to remove gravel
and debris, and ground or milled to a fine powder.
Dry the sample if it is moist and cohesive. The sample can be dried in any of
several ways. Choose one of the following:
•
•
Oven dry the sample for approximately 2 hours at 150° C, until the
sample reaches a constant weight. Note: Oven drying is
inappropriate when volatile compounds may be present in the
sample. For example, lead present as tetraethyl lead would be driven
off by the heat of drying. Some forms of mercury and arsenic are
volatile. Air drying will preserve more of these volatile substances.
Air dry the sample overnight at room temperature in a shallow pan.

Cleaning Your Equipment:

NITON XL3 Analyzer User's Guide 1-45