Method for determining the true specific gravity of refractory materials by gas density meter - Master's thesis - Dissertation

American Standard ASTM C604 –98 Method for determining true specific gravity of refractory materials by gas density meter 1. Scope 1.1 This method is particularly suitable for measuring the true specific gravity of solid materials that are prone to water absorption, deliquescence, or hydration. These types of substances are not appropriate for testing using the C135, C128, or C188 methods. 1.2 When following this standard, users should develop and implement safety measures and health precautions based on the situation during operation. 2. References 2.1 ASTM Standards: C128 – Test Method for Specific Gravity and Absorption of Fine Aggregates C135 – Determination of True Specific Gravity of Refractory Materials by Water Pycnometer C188 – Test Method for Density of Hydraulic Cement 3. Key Points of the Method 3.1 The sample must be ground into a fine powder to ensure that gas can penetrate all pore spaces. Breaking the sample through a #325 sieve is typically sufficient. Before the experiment, the powder is dried to remove free moisture and bound water. The volume is measured using a gas densitometer, and the density is calculated by dividing the mass (in grams) by the volume (in cm³). This value represents the specific gravity relative to water at 4°C. 3.2 The gas density meter operates with two chambers and two pistons. When the connecting valve is closed, movement of one piston causes an imbalance in pressure. To maintain balance, the other piston must move accordingly. 3.3 When a sample is placed in chamber B, and the valve is closed, moving both pistons from position 1 to 2 creates an imbalance. Adjusting piston B to position 3 restores balance, and the displacement between positions 2 and 3 corresponds to the sample volume. This displacement is calibrated and read directly from a digital device in cm³. 4. Purpose and Application 4.1 True specific gravity is the ratio of the material’s true density to that of water at a given temperature. It is a key physical property influenced by chemical composition and mineral structure. 4.2 This method is especially useful for hydrated materials, as traditional methods like C135 may not be applicable. 4.3 For refractory materials, specific gravity helps classify materials, distinguish minerals, calculate porosity, and support various analytical tests. 4.4 It serves as a primary standard for technical classification, quality control, research, and product development. It can also act as an arbitration method in material procurement agreements. 4.5 The method requires strict adherence to several conditions: representative sampling, proper grinding, no contamination, removal of moisture without altering the material, use of helium, and precise execution. Deviations may affect accuracy. 4.6 Even with fine particle size, some closed-cell pores may remain. Variations in voids between samples can lead to small differences in results. Therefore, the measured value is close to the true specific gravity but not always exact. Careful analysis is needed when comparing similar materials. 5. Equipment 5.1 Analytical balance (200g capacity, 10mg sensitivity) 5.2 Dryer with magnesium perchlorate desiccant 5.3 Muffle furnace (up to 1000°C) 5.4 Crushing equipment (to <45µm via No. 325 sieve) 5.5 Helium cylinder with regulator and pressure gauge 5.6 Gas pycnometer with external cleaning valve system 6. Sample Preparation 6.1 Grind enough sample to perform three measurements. Use approximately 100g per test. 6.2 After grinding, burn the sample at high temperature to remove moisture and organic matter without causing agglomeration. Hydratable materials require at least 600°C for 3 hours. 6.3 Cool the sample in a desiccator with magnesium perchlorate before measurement. 7. Measurement Procedure 7.1 Calibrate the densitometer with a standard volume according to the manual. 7.2 Weigh the sample to the nearest 10mg after placing it in the sample cup. Ensure temperature difference is less than 2°C. 7.3 Place the sample in the densitometer chamber, clean with dry helium, and ensure pressure does not exceed 13.8 PSI. 7.4 Measure the sample volume using the instrument's standard procedure, allowing 60 seconds for temperature equilibrium. 7.5 Repeat measurements until two consecutive values differ by less than 0.05 cm³; take the average. 8. Calculation 8.1 True density is calculated using S = W/V, where S is density (g/cm³), W is mass (g), and V is volume (cm³). 9. Reporting 9.2 For three samples, if the difference is less than 0.01, report the average to two decimal places. 10. Precision and Accuracy 10.1 Interlaboratory tests were conducted on granular alumina and MULCOA 47. Results showed repeatability and reproducibility values, with allowable error calculated as standard deviation divided by 2.8. 10.2 No significant deviation was found due to lack of reference materials. 11. Keywords Gas pycnometer, hydrated materials, refractory materials, true specific gravity.

Modular Plugs

We are Manufacturer and Supplier to offer modular plugs in standard configurations to terminate modular cords for patching or work area applications. Our Modular plugs can be terminated to the exact cable length needed in order to maintain a neater, more organized installation. The modular plugs terminate twisted-pair cable with 26 - 22 AWG (0.40mm - 0.64mm) solid or 7-strand conductors with an insulated conductor diameter of 0.86 - 0.99mm (0.034 - 0.039 in.). All modular plug contacts have 50 microinches minimum of gold plating over nickel and meet TIA-968-A and IEC 60603-7 specifications.

Modular Plug is the name given to a family of electrical connectors originally used in telephone wiring and now used for many other purposes. Many applications that originally used a bulkier, more expensive connector have now migrated to modular connectors. Probably the most well known applications of modular connectors are for telephone jacks and for Ethernet jacks, both of which are nearly always Modular Connectors.

Modular Connectors were originally used with the registered jack system, which precisely describes how the connectors are wired for telecommunications. The registered jack specifications define the wiring patterns of the jacks, not the physical dimensions or geometry of the connectors of either gender. Instead, these latter aspects are covered by ISO standard 8877, first used in ISDN systems. TIA/EIA-568 is a standard for data circuits wired on Modular Plug&Connectors.

Other systems exist for assigning signals to modular connectors; physical interchangeability of plugs and jacks does not ensure interoperation, nor protection from electrical damage to circuits. For example, modular cables and connectors have been used to supply low-voltage AC or DC power and no clear standard exists for this application.

RJ45 Modular Plugs, RJ11 Modular Plugs, AMP Modular Plugs, Modular Connector, Cat6 Modular Plugs, Cat5e Modular Plugs

NINGBO YULIANG TELECOM MUNICATIONS EQUIPMENT CO.,LTD. , https://www.yltelecom.com