NB/SH/T 0834-2010 Determination of moderate high-temperature piston deposits of engine oils — Thermal oxidation simulation test method (TEOST MHT)

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Incomplete source card: Sections 9, 10, 11, 12, 13, 14 are absent from the available source. Only available content is translated; source completion is pending.

Card type: Test method

1. Method number / full title / English name / replacement relationship

• Standard number: NB/SH/T 0834—2010
• Chinese full title: Determination of moderate high-temperature piston deposits of engine oils — Thermal oxidation simulation test method (TEOST MHT)
• English name: Standard test method for determination of moderately high temperature piston deposits by thermo-oxidation engine oil simulation test (TEOST MHT)
• Replacement relationship: not provided in the available source (the foreword only states modified adoption of ASTM D7097-06a, and does not mention replacement of any old standard)
• Adoption relationship: modified adoption of ASTM D7097-06a "Determination of moderate high-temperature piston deposits of engine oils — Thermal oxidation simulation test method (TEOST MHT)"
• Main technical differences from ASTM D7097-06a (foreword): referenced standards are changed to the corresponding current standards of our country; the wording of repeatability and reproducibility is modified according to our country's practice
• Publication/implementation: published by 2010-05-01, implemented by 2010-10-01
• Issuing authority: National Energy Administration
• Custodianship: Petroleum Fuels and Lubricants Subcommittee of the National Technical Committee for Standardization of Petroleum Products and Lubricants (SAC/TC280/SC1)
• Drafting units: Lubricant Research and Development (Shanghai) Center of China Petroleum & Chemical Corporation, Dalian Lubricant Research and Development Center of PetroChina Company Limited
• Main drafters: Yang Huiqing, Liu Jianxin, Wang Yaping

2. Scope of application and non-applicability

• 1.1 specifies a method in which, under the oxidation and catalysis conditions of 285 ℃, 8.5 g engine oil is repeatedly passed as a thin oil film over a specially structured test rod, and then the deposits formed on the rod are determined.
• 1.1 interlaboratory study: the applicable range of TEOST MHT is 10 mg–100 mg; experience shows that it may also be applicable when the deposit mass is 1 mg–150 mg or greater.
• 1.2 uses patented instruments, methods, and a patented, numbered, and registered deposit rod, the number of which can be traced to the manufacturer; the deposit rod is specially made for the purpose and precision of this method. Note: the validity of the patent and the risk of infringement shall be determined and borne by the user.
• 1.3 uses International System of Units [SI] units.
• 1.4 involves hazardous materials, operations, and equipment; the standard is not intended to address all safety issues; users should establish appropriate safety precautions before use and determine the applicability of relevant regulatory limitations.
• Non-applicability: no explicit "non-applicability" clause is provided in the available source.

3. Method principle

• 4 method summary: fully and uniformly mix a sample of 8.5 g (the source source-text extraction writes "8 4g", requires confirmation (source-text extraction)) with 0.18 g (the source source-text extraction writes "0.18", unit requires confirmation (source-text extraction)) organometallic catalyst, introduce a fixed amount of air, and circulate in a TEOST MHT instrument; a thermocouple is used to control heating of the deposit rod so that the temperature is controlled at 285 ℃, the sample flows spirally down along the metal coil on the deposit rod, for a total of 24 h cycles, to evaluate the tendency of engine oil to form deposits under moderate high-temperature oxidation conditions.
• The deposit rod must be weighed before and after the test; deposits washed off the deposit rod should also be collected, dried, and weighed.
• Main factors affecting test precision: manufacturing precision of the deposit rod wound with metal coil, coating treatment of the coil, air flow rate, amount of catalyst, and degree of mixing with the sample.
• 3.2 deposit rod deposits: deposits formed by oxidation on the surface of the deposit rod when the oil film flowing over the deposit rod contacts air at high temperature; after cleaning and drying, the net increase in deposit mass is obtained by weighing.
• 3.3 filter deposits: particulate matter washed from the deposit rod after the test and collected with a special multilayer filter cartridge.
• 3.6 total deposits: the sum of the deposit masses on the deposit rod and the filter.
• 3.7 volatile oil: oil collected after oil vapor condenses in the jacket (the source source-text extraction writes "jacket", requires confirmation (source-text extraction)).

4. Reagents and materials (purity / preparation)

• 7.1 sandpaper: 15 μm (the source source-text extraction writes "15p", requires confirmation (source-text extraction))
• 7.2 acetone: analytical grade. Warning: flammable and explosive, toxic (the source source-text extraction writes "has", requires confirmation (source-text extraction))
• 7.3 air: oil-free, clean, dry compressed air (the source source-text extraction writes "pool element dry) thorough", requires confirmation (source-text extraction)); when the gas source pressure is above 690 kPa, it can be regulated within 15 kPa~100 kPa
• 7.4 cyclohexane or other alkane solvents of equivalent volatility: analytical grade; naphthenic or aromatic hydrocarbon solvents should not be used; this standard collectively refers to them as "hydrocarbon solvents". Note: the volatility of the alkane solvent should ensure that the solvent on the deposit rod and filter evaporates in time. Warning: flammable and explosive
• 7.5 catalyst: contains (the source source-text extraction writes "contains", composition requires confirmation (source-text extraction)) ... and tin (the source source-text extraction writes "along and tin", requires confirmation (source-text extraction)); the composition is similar to engine oil deposits; for long-term storage, the catalyst may be refrigerated (the source source-text extraction writes "hidden in the refrigerator", requires confirmation (source-text extraction)), and should be allowed to rise to room temperature several hours before use before opening the can (to eliminate solidified matter); it may be temporarily sealed and stored at room temperature for 4 weeks
• 7.6 certified reference oils: certified low-deposit reference oil (LDF, 10 mg–15 mg, the source source-text extraction writes "10mg–15p", requires confirmation (source-text extraction)); certified medium-deposit reference oil (MDF, 40 mg–50 mg); certified high-deposit reference oil (HDF, 70 mg–90 mg, the source source-text extraction writes "FDr", requires confirmation (source-text extraction))
• 7.7 oil for depth calibration of pump speed and temperature control thermocouples TPC-1: an oil that suppresses high deposits and does not form obvious deposits on the deposit rod when calibrating the pump and temperature controller
• 7.8 varnish cleaning liquid: used to clean varnish on the glass cover, end nuts, and other equipment after the test; other glass cleaners with varnish cleaning function may also be used

5. Instruments and equipment

• 6.1 MHT instrument (including fittings and assemblies used for the TEOST MHT test procedure)
• 6.1.1 deposit rod jacket equipment
  • 6.1.1.1 insulator: a special insulating part that presses the deposit rod O type ring into the end nut, keeping the deposit rod centered in the end nut (to prevent sample leakage from the lower end nut, see Figure 2 and Figure 3)
  • 6.1.1.2 (the source number is repeated as 6.1.1.1, requires confirmation (source-text extraction)) deposit rod: a patented design, a metal steel tube wound with specially treated steel wire (the source source-text extraction writes "steel wire type number", requires confirmation (source-text extraction)); the inner bore of the steel tube is precisely designed to contact the probe; deposit rods with serial numbers should be used when conducting the TEOST MHT test (see Figure 2, Figure 3, Figure 4). Note: test accuracy is determined by the manufacturing uniformity and usage of the deposit rod; each deposit rod is coded and traceable to the manufacturer
  • 6.1.1.3 nut: keeps the glass cover and the upper end of the deposit rod in the proper position, and guides air and sample separately into the deposition zone (see Figure 2 and Figure 4)
  • 6.1.1.4 end nut: keeps the glass cover and the lower end of the deposit rod in the proper position, and provides an outlet for the sample to flow into the sample bottle, then through the circulation pump into the oil inlet tube (see Figure 5)
  • 6.1.1.5 end nut: used to compress the small O type ring wound around the deposit rod and to fix and seal the oil inlet tube and air inlet tube
  • 6.1.1.6 glass cover: an outer tube cover used to seal the deposit rod and guide volatile oil into the collection bottle (see Figure 2~Figure 5)
  • 6.1.1.7 spring clip: used to clamp the collection bottle in the proper position (see Figure 5 and Figure 6)
  • 6.1.1.8 oil inlet tube: the channel that introduces the sample to the top of the deposit rod
  • 6.1.1.9 large O type ring: oil-resistant and heat-resistant, seals the lower end nut and glass cover (see Figure 3)
  • 6.1.1.10 small O type ring: oil-resistant and heat-resistant, isolates air and sample between the deposit rod and the end nut (see Figure 3)
  • 6.1.1.11 pump outlet tube: elastic transparent vinyl plastic hose, outer diameter 3.2 mm, one end flared, transports the sample from the pump to the oil inlet tube (see Figure 5)
  • 6.1.1.12 sample bottle: 25 mL Erlenmeyer flask with side arm, first weighed with catalyst and sample, then used to inject the sample into the circulation system (see Figure 5 and Figure 6)
  • 6.1.1.13 stainless steel hex bolts and busbar end pieces: ensure the deposit rod is fixed in the end busbar component
  • 6.1.1.14 thermocouples: one pair, stainless steel sheath, diameter 1.57 mm, length 150 mm; the J type is used to control the test temperature (deposit rod), and the K type is used for protection against overheating
  • 6.1.1.15 thermocouple locking ring: fixes the insertion depth of the thermocouple to ensure the tip is in the correct position when the thermocouple is inserted into the deposit rod
  • 6.1.1.16 collection bottle clamp: used to clamp the volatile collection bottle so that it is in the proper position on the glass cover (see Figure 2)
• 6.1.2 air flow control device: used to set the air flow rate at the selected flow level
  • 6.1.2.1 soap film flowmeter: a device used to precisely set the air flow rate and to calibrate the flow rate within the range of 1 mL/min~30 mL/min (see Figure 1)
  • 6.1.2.2 calibrated flowmeter: capable of measuring air flow of 1 mL/min~20 mL/min and providing continuous readings
  • 6.1.2.3 handheld digital flowmeter: not essential, used to monitor air flowing into or out of the glass cover, with flow readings that can be accurately controlled at 10.0 mL/min±0.1 mL/min
  • 6.1.2.4 Precision digital mass flow controller: not essential, precisely controls the flow of air entering (see Figure 1a)
  • 6.1.2.5 Stopwatch: accurate to 0.01 s
• 6.1.3 Filter flask apparatus: filters the sediment particles washed off the deposition rod (see Figure 7)
  • 6.1.3.1 Filter: a multi-layer filter that can match the end of the filter funnel and is specially made for the TEOST MHT test
  • 6.1.3.2 Filter funnel: a specially made funnel of 400 mL capacity, with the neck downward to the filter funnel length of 10 mL, the lower part connected to the filter tube apparatus
  • 6.1.3.3 Filter tube apparatus: a metal or polyethylene tube, inserted into the vacuum flask through a 8# rubber stopper, and matched with the lower outlet of the filter
  • 6.1.3.4 Vacuum flask: 1000 mL, used to collect the hydrocarbon solvent after filtration and washing
  • 6.1.3.5 Vacuum source: should have sufficient suction to draw the hydrocarbon solvent and oil through the filter, and can ensure the filter gets the necessary (original source-text extraction as "necessary", requires confirmation against the source standard (source-text extraction))
  • 6.1.3.6 Steel wire rod: stainless steel, diameter 1 mm–1.5 mm, length 300 mm–350 mm, used to guide the sediment retained on the filter funnel near the filter (original source-text extraction as "the part near the filter that continues to hurt", requires confirmation against the source standard (source-text extraction))
• 6.2 Auxiliary apparatus (necessary or helpful for the test)
  • 6.2.1 Balance: sensitivity of 0.2 mg (original source-text extraction as "awn: sensitivity of 0.2mg", requires confirmation against the source standard (source-text extraction)), used to weigh the sediment
  • 6.2.2 Catalyst syringe: 100 μL capacity, used for precise measurement of catalyst
  • 6.2.3 Pipette: disposable glass or plastic pipette or dropper
  • 6.2.4 Extraction test tubes: three, 120 mm long (original source-text extraction as "120m long", requires confirmation against the source standard (source-text extraction)), made of glass or plastic resistant to hydrocarbon solvents
  • 6.2.5 Temperature recorder: not essential, 24 h during the test tracks the temperature at the upper part of the deposition rod thermocouple
  • 6.2.6 Thermocouple depth insertion gauge: not essential, used to set and check the thermocouple depth, using a millimeter scale
  • 6.2.7 Bottle and matching bottle cap: 10 mL or larger capacity, bottle mouth diameter 11.5 mm, outer diameter 20 g (original source-text extraction as "outer diameter 20g", unit requires confirmation against the source standard (source-text extraction)), used to collect the volatile oil generated during the test and the sample at the end of the test (Figure 2)
  • 6.2.8 Aluminum circular or dish-shaped container: preferably made of aluminum, diameter 7 cm~10 cm, to prevent the deposition rod from rolling, there are two notches in the radial direction (see Figure 8)

6. Recommended operating conditions

• 8 Instrument program settings
  • 8.1 Temperature control PID setting: adjust the thermocouple sensitivity and response value (PID set value), to minimize the deviation of the temperature value during operation; the instrument manual has recommended settings and adjustment methods
  • 8.2 Temperature controller setting: set the temperature control program according to the instrument manual instructions, to maintain the temperature at 24 h 285 ℃
  • 8.3 If using a paper tape recorder: set the paper feed speed to 100 mm/h, but at this time do not lower the pen or turn on the paper tape drive
  • 8.4 If using other methods for continuous temperature recording: should be prepared to receive temperature information
• 9 Calibration and standardization
  • 9.1 Calibrate air flow rate (optional process 9.1.1 or 9.1.2)
    • 9.1.1 Calibrate air flow with a mass flow controller
      • 9.1.1.1 Before each test, use a soap film flowmeter or other higher-level calibration equipment to check and calibrate the flow controller. Note: the TEOST MHT procedure is very sensitive to flow fluctuations, and it is necessary to use calibration equipment to verify the air flow
      • 9.1.1.2 Assemble the soap film flowmeter and mass flow controller as shown in Figure 1a
      • 9.1.1.3 Connect a clean, dry air source to the mass flow controller, and set the air source controller to the allowable range of the mass flow controller (usually at 100 kPa~140 kPa)
      • 9.1.1.4 Connect the mass flow controller to the soap film flowmeter
      • 9.1.1.5 Let the air flow through the flow controller and the soap film flowmeter
      • 9.1.1.6 Squeeze the rubber bulb of the soap film flowmeter (half filled with liquid soap water), forcing the soap water upward into the glass cylinder and wetting the tube wall; avoid foaming of the mixed liquid
      • 9.1.1.7 Gently squeeze the rubber bulb to generate a bubble above the air inlet near the bottom of the soap film flowmeter; let the air flow lift the bubble to the top of the tube
      • 9.1.1.8 Use a stopwatch to measure the time required for the bubble to rise to 5 mL
      • 9.1.1.9 Calculate the flow rate using formula (1) or (2): V=5×60/S (1); or simplified to V=300/S (2). Where: V— flow rate, mL/min (original source-text extraction as "m", requires confirmation against the source standard (source-text extraction)); S— time required for the bubble (to rise to 5 mL), min
      • Adjust the needle valve of the flow controller so that the soap film tube flow reaches 10.2 mL/min±0.2 mL/min, thereby calibrating the mass flow controller; when using the data collected on the mass flow controller (original source-text extraction as "the data collected on the mass flow controller 122-02m1/mlrl", requires confirmation against the source standard (source-text extraction))
      • Note: When referring to a suitable air flow, some models of flowmeters may allow the reading to be corrected to a corrected value
    • 9.1.2 Calibrate air flow with a soap film flowmeter
      • Before each test, use a soap film flowmeter or other higher-level calibration equipment to calibrate the analog or digital flowmeter
      • Assemble the soap film flowmeter and the flowmeter equipped with a needle valve, as shown in Figure 1a or Figure 1c (original source-text extraction as "Figure 1a or Figure 1e", requires confirmation against the source standard (source-text extraction)); use a handheld flowmeter
      • Connect a dry air source to the flowmeter, and set the air source controller within the allowable range of the flowmeter
      • Insert one end of the air inlet tube into the rubber hose connected to the soap film flowmeter, and check the sealing of the connection point with soap solution
      • Perform steps 9.1.1.4~9.1.8
      • Adjust the needle valve, reset the bubble rise rate so that the flow rate reaches 10.2 mL/min±0.2 mL/min
  • 9.2 Check oil pump flow rate: according to the manufacturer's manual requirements, set the oil pump flow rate to 0.25 g/min±0.01 g/min (original source-text extraction as "0.25g/min ±0.01g/mp", requires confirmation against the source standard (source-text extraction))
  • 9.3 Temperature controller setting: according to the manufacturer's manual requirements, set the temperature controller to the test temperature of 285 ℃
  • 9.4 Verify temperature control thermocouple: calibrate the deposition rod temperature control thermocouple in a liquid bath or sand bath at 285 ℃, and if necessary, adjust the temperature controller compensation (original source-text extraction as "compensation", requires confirmation against the source standard (source-text extraction)) to match; in the absence of a liquid bath or sand bath, boiling distilled water can be used for verification at 100 ℃. Before reusing the thermocouple, use sandpaper to wipe off corrosion or deposits on the thermocouple surface; the surface after scrubbing should be metallic luster, especially in the temperature-sensitive area at the end of the thermocouple; but do not over-scrub the thermocouple surface, because the thermocouple wall (will) be damaged
  • 9.5 Determination, setting and use of the appropriate position of the thermocouple: according to the method specified in the manufacturer's manual, find the hottest point of the inner hole of the deposition rod
    • 9.5.1 (original source-text extraction as "9.5.", requires confirmation against the source standard (source-text extraction)) Note the (requirements) of the thermocouple depth insertion gauge for the thermocouple depth
    • 9.5.2 Install a thermocouple locking ring on the upper part of the thermocouple, so that when inserted into the inner hole of the deposition rod, the thermocouple temperature sensing area is at the position determined when measuring the (hottest point) depth
    • 9.5.2.1 Before each test, use the thermocouple depth insertion gauge to check whether the thermocouple insertion depth is correct
    • 9.5.3 Gently insert the thermocouple (see note after 9.5.4) into the inner hole of the deposition rod, so that the locking ring contacts the upper end of the protruding part of the deposition rod. Note: If the thermocouple is inserted too deep (original source-text extraction as "strong text want path", requires confirmation against the source standard (source-text extraction)), the locking ring may (move), causing the thermocouple sensing area to be in the wrong position
    • 9.5.4 Adjust the paper tape recorder or other temperature recorder to record the temperature sensed by the temperature control thermocouple. Note: To determine the effectiveness of the thermocouple and the abnormality caused by unstable local power supply, it is very important to continuously record the temperature of the temperature control thermocouple with maximum sensitivity
  • 9.6 Install the overheat thermocouple according to the manufacturer's manual
  • 9.7 According to clause 10.1 and chapter 13 (original source-text extraction as "i of chapter 13", requires confirmation against the source standard (source-text extraction)), use certified reference oil to verify the TEOST MHT standard procedure

7. Sampling and sample preparation

• 10 Sample preparation
  • 10.1 Before testing unknown samples, ensure the functionality of the TEOST MHT instrument by testing certified reference oil; select one of the certified reference oils mentioned in clause 7.6, and operate according to clauses 10.2~10.8
  • 10.2 Confirm that the heating switch of the TEOST MHT instrument is in the off state to prevent accidental startup of the equipment; then turn on the main power switch and let the instrument electronic components warm up for 30 min or longer
  • 10.3 Ensure the pump switch is in the off state
  • 10.4 Ensure the thermocouple is clean and free of contamination (see 9. (4)); catalyst bottle and sample container (original source-text extraction as "catalyst bottle and sample container", requires confirmation against the source standard (source-text extraction))... three times, to ensure the two components are mixed evenly before use
  • 10.5 Place a clean (sample) bottle on the precision balance, weigh the tare (zero the container mass displayed on the balance)
  • 10.6 Use a microsyringe to add the pre-calculated amount of catalyst to the sample, obtaining a 8.5 g sample-catalyst mixture; record the catalyst mass and (accurate to) 0.0001 g (original source-text extraction as "2001g", requires confirmation against the source standard (source-text extraction)); the amount of catalyst added is within 0.0003 g of the required mass. Note: Certified catalyst (on the bottle) indicates the required sample mass for the mixture according to the sample/catalyst ratio
  • 10.7 Weigh again the required mass of sample into the sample bottle, so that the total mass of the sample-catalyst mixture is 8.5 g±0.05 g; the mass of sample added should be within 0.01 g of the mass required by the corresponding catalyst/oil ratio marked on the catalyst bottle; if more oil than required is added, the sample must be re-prepared. Note: An electronic file with a general calculation table can be purchased from the ASTM Test Monitoring Center (TMC) to determine the corresponding catalyst/sample mass
  • 10.8 Place a magnetic stir bar that does not (contain) polytetrafluoroethylene into the sample bottle; place the sample bottle on the magnetic stirrer on the TEOST platform and stir; stirring time 30 min~60 min (maximum 60 min); do not heat the mixture; do not stir the mixture too vigorously, especially avoid a large vortex (to) prevent splashing of the mixture
  • Arrange the test process reasonably, hardware installation and sample preparation can be carried out simultaneously, so that the test can be started after only a short preparation time

8. Analysis Procedure

• 11 Installation
  • 11.1 Install new large O O-rings in the nuts at both ends. If the operator wants to determine the mass of volatile oil, recovered oil, and glass cover deposits, they should weigh and record the mass of the volatile oil collection bottle, recovered oil bottle, and the cleaned and dried glass cover
  • 11.2 With a gentle spiral motion, insert the upper end of the glass cover flatly into the upper nut; avoid crushing the glass of the glass cover, ensure that the opening of the glass cover (as shown in Figure 3) faces the opening of the corresponding oil inlet tube in the upper nut
  • 11.3 Clean and weigh the deposition rod
    • 11.3.1 Use a weighing pan: select a weighing pan (as shown in Figure 8), weigh accurately to 0.0001 g; cover the weighing pan when not in use to avoid (contamination) by airborne particles; if the balance fluctuates, the weighing pan can be briefly grounded to eliminate static electricity
    • 11.3.2 Once preparation of the deposition rod begins, handle it carefully, do not place the deposition rod anywhere other than the weighing pan; keep it covered when not in use
    • 11.3.3 When moving and cleaning the deposition rod, be careful not to change the pitch and length of the coil. Note: The coil of the deposition rod has a specified pitch preset by the manufacturer, and its tightness is adjusted so that (it) can slide up and down the deposition rod but not too loosely
    • 11.3.4 Clean the inside and outside of the deposition rod with a hydrocarbon solvent—hold the deposition rod with gloves resistant to hydrocarbon solvents to prevent oils secreted by the skin from affecting the surface of the deposition rod. Note: If the gloves react with the hydrocarbon solvent, a (dissolved) film or residue will be left on the gloves
    • 11.3.5 Using a test tube brush soaked in acetone, first push the brush along the direction of the deposition rod hole to the bottom, scrub the inner hole of the deposition rod, then use a new acetone-soaked test tube brush to clean the inner hole again in the opposite direction; be extremely careful when holding and cleaning the deposition rod to avoid deforming the coil
    • 11.3.6 Wearing hydrocarbon (solvent-resistant gloves)…… (original source-text extraction incomplete, requires confirmation against the source standard (source-text extraction))
    • 11.3.7 Using thumb and index finger (hold the deposition rod) to clean the inner and outer surfaces of the deposition rod hole with acetone; vacuum dry the interior of the deposition rod; do not use compressed air to dry the deposition rod; only dry the outer surface of the deposition rod in ambient air
    • 11.3.8 Place the deposition rod into the pre-weighed weighing pan (see Figure 8); weigh the deposition rod and weighing pan, with two consecutive weighings differing within 0.0001 g; record this value as the initial mass of the deposition rod and weighing pan, subtract the mass of the weighing pan from the total mass to obtain the mass of the deposition rod
    • 11.3.9 After measuring the mass of the weighing pan and deposition rod, cover the weighing pan and store it aside for use at the end of the 24 h deposition test
  • 11.4 Complete the installation of the deposition rod housing (see Figure 2~Figure 5)
    • 11.4.1 Select the already assembled glass cover and upper nut (see 11.2), carefully pass the end of the deposition rod with the serial number upward through the glass cover/upper nut assembly, until one end of the deposition rod protrudes about 25 mm from the screw hole of the upper nut
    • 11.4.2 Place two new O O-rings on the protruding part of the deposition rod
    • 11.4.3 Place a ceramic insulator on the top of the deposition rod, with the larger diameter end facing the O O-ring; push the ceramic insulator so that the O O-ring contacts the threaded neck of the upper nut, as shown in Figure 2
    • 11.4.4 Place an end nut on the protruding part of the deposition rod, and insert the smaller diameter end of the ceramic insulator into the hole of the end nut, press the end nut with fingers so that the two O O-rings tightly contact the neck of the upper nut, forming a seal and insulation between the deposition rod and the end nut
    • 11.4.5 Ensure that the spiral coil of the deposition rod rests against the bottom of the narrow middle section of the deposition rod
    • 11.4.6 Insert the bottom of the deposition rod into the lower nut, continue inserting until it passes through the lower nut of the glass cover (as shown in Figure 2, Figure 3); similarly, insert spirally without crushing the glass cover
    • 11.4.7 Repeat steps 11.4.2~11.4.4 for the bottom of the deposition rod and the lower nut, as shown in Figure 3, to complete all assembly work of the deposition rod housing except for the oil inlet tube connection
    • 11.4.8 Ensure that the lengths of the upper and lower protruding parts of the deposition rod are equal; if necessary, loosen the end nuts and move the deposition rod to ensure equal protruding lengths
  • 11.5 Complete the connection of the deposition rod housing assembly to the busbar
    • 11.5.1 Ensure that the upper and lower sections of the busbar assembly are free of oil or other impurities that could impede current after the test begins; if necessary, wipe the busbar contact area with a paper towel soaked in hydrocarbon solvent (see 7.4) and dry
    • 11.5.2 Remove one top screw; then rotate the cap to expose the V slot, during the test, the upper protruding part of the deposition rod sits in the slot to form electrical contact
    • 11.5.3 Loosen the lower busbar screw to a certain extent, so that the bottom protruding part of the deposition rod (now embedded in the deposition rod assembly) can be carefully lowered onto the overheat thermocouple protruding between the bottom busbar and its nut; this is the ideal method for installing the deposition rod device on the busbar, while inserting the overheat thermocouple without bending
    • 11.5.4 Place the upper end of the deposition rod against the busbar assembly, then tighten the busbar nut onto the upper protruding part of the deposition rod, install the hex screw, tighten slightly, and wait for the next step to be completed
      • 11.5.4.1 The hex screw connecting the busbar nut to the busbar should maintain sufficient freedom to be easily pressed down, pass through the hole of the busbar nut, and be screwed onto the busbar
    • 11.5.5 Adjust the upper part of the deposition rod so that it protrudes 1 mm~2 mm above the upper end of the busbar nut, then use a suitable hex wrench to tighten 4 screws (two in each of the upper and lower busbar nuts)
    • 11.5.6 Tighten the busbar nuts evenly so that the gaps between the busbar and its nuts on both sides of the deposition rod are consistent; ensure that when tightening the busbar nuts, the ceramic insulators or thermocouple locking rings of the upper and lower end nuts are not squeezed by the busbar nuts; good contact between the deposition rod and the busbar is required to conduct a large current at low voltage
    • 11.5.7 Insert the overheat thermocouple into the deposition rod until its collar contacts the bottom of the deposition rod or the lower busbar
    • 11.5.8 Before each test, check whether the locking ring of the temperature control thermocouple is locked and at the correct insertion depth; the insertion depth is specified in 9.5
    • 11.5.9 Insert the temperature control thermocouple along the inner hole of the deposition rod to the locking ring; when inserting, be careful not to bend the thermocouple
  • 11.6 Connect the rigid oil inlet tube and the oil flow flexible tube system
    • 11.6.1 Connect a new oil inlet tube when used for the first time (see Figure 3)
      • 11.6.1.1 Before proceeding with the following steps, confirm that the deposition rod housing installation has been completed; then follow the steps described in 11.6.1.2~11.6.1.7 to perform the initial setting of the metal ferrules. Note: When setting the metal ferrules, the ideal method is to fix the deposition rod housing assembly on the busbar
      • 11.6.1.2 With the two metal ferrules in the proper position, insert the beveled mouth into the oil inlet tube inlet nut, then facing the beveled end of the oil inlet tube, clamp the outer diameter of the oil inlet tube
      • 11.6.1.3 Gently push the oil inlet tube to drive the two metal ferrules into the internal conical opening of the oil inlet tube in the upper nut; the bevel of the oil inlet tube lightly contacts the metal coil on the deposition rod (Figure 3)
      • 11.6.1.4 Use the oil inlet tube inlet nut to push the two metal ferrules to the neck of the oil inlet tube, rotate the nut to the neck until resistance from the metal ferrules is felt
      • 11.6.1.5 Ensure that the bevel of the oil inlet tube lightly contacts the metal coil on the deposition rod and the opposite oil inlet tube port faces down, with the deposition rod housing assembly standing vertically (see Figure 3); then tighten the nut about 1/2 turns to place the conical metal ferrules onto the rigid short tube
      • 11.6.1.6 While keeping the oil inlet tube inlet nut tight, gently try to move the oil inlet tube backward to break contact with the metal coil on the deposition rod, thereby testing whether the metal ferrule and oil inlet tube are in good contact
      • 11.6.1.7 If the oil inlet tube can be moved back, then lightly contact the bevel with the metal coil on the deposition rod, and tighten the inlet nut again enough so that the inlet tube does not move back and forth. Note: These steps install the metal ferrules on the plastic tube, so that when the non-beveled port of the oil inlet tube faces down, the bevel of the oil inlet tube is always in a reasonable relative position with the deposition rod; but at this time the metal ferrules are not fully tightened, so they cannot prevent lateral movement of the non-beveled port of the oil inlet tube; in most cases, it is not necessary to tighten the metal ferrules to the extent that such lateral movement cannot occur; if you really want to do so, please contact the manufacturer for guidance
    • 11.6.2 Connect a previously used oil inlet tube (see Figure 3) to the designated upper nut
      • 11.6.2.1 Insert the beveled end of the oil inlet tube through the oil inlet tube nozzle of the upper nut, so that its tip reaches and lightly contacts the coil wound on the deposition rod; tighten the oil inlet tube inlet nut
      • 11.6.2.2 Oil inlet tube nozzle position: A: The tip of the oil inlet tube should contact the metal wire on the deposition rod, ensuring that the sample flows down along the specially treated metal coil in a spiral motion without directly dripping onto the bottom end cap or flowing down the inside of the glass cover without passing the deposition rod; B: After repeated use, the oil inlet tube nozzle (the beveled end) will age and carbonize, making it difficult to bend; ensure that the sample flows accurately onto the deposition rod, after 25 tests or when carbonization of the oil inlet tube nozzle is found, a new oil inlet tube should be used. Note: When the oil inlet tube nozzle is completely aged, the sample will flow back outside the tube, along the inner wall of the glass cover into the glass cover and then into the volatile bottle, thereby affecting the test results
  • 11.7 Connect the oil inlet pipe to the oil pump outlet with a transparent, oil-resistant, elastic plastic tube with an outer diameter of 3.2 mm
  • 11.8 Confirm the air flow rate
    • 11.8.1 Adjust the air flow rate to 10.0 mL/min, then according to the provisions of clause 9.1, check the air flow rate to the outer jacket of the deposition rod
    • 11.8.2 Connect the air inlet pipe to the air inlet pipe on the upper end nut, tighten the nut by hand (see Figure 4); place a rubber stopper on the lower end nut to prevent air leakage from the opening
    • 11.8.3 To ensure the air flow rate through the glass cover is 10 mL/min±0.2 mL/min, connect a soap film flowmeter or a calibrated digital handheld flowmeter to the volatile transport tube, so that all air flowing out from that opening passes through the soap film flowmeter or handheld digital flowmeter
    • 11.8.4 Measure the air flow rate at the outlet of the volatile transport tube; before measurement, ensure the pump switch is in the off position
      • 11.8.4.1 If the air flow rate is less than 10 mL/min±0.2 mL/min, tighten the oil inlet pipe nut on the upper end nut and the end nuts of the two O type rings on the upper and lower end nuts used to compress the ceramic insulator and fix the deposition rod (see Figure 3, Figure 4)
      • 11.8.4.2 If the air flow rate is still less than 10 mL/min±0.2 mL/min, use a dropper filled with detergent-water solution to check for air leaks along the O type rings of the upper and lower end nuts and check for bubbles; if bubbles are seen, first remove the glass cover and check whether the glass cover has cracks or fragments; if not, replace an end nut O type ring and retest; if bubbles are still found, contact the manufacturer
      • 11.8.4.3 If the air flow rate is still less than 10 mL/min±0.2 mL/min, disconnect the air pipe from the upper end nut and check the air flow rate again (see clause 9.1)
      • 11.8.4.4 If the air flow rate here is correct, replace the metal ferrule on the air inlet pipe with a plastic ferrule, and tighten the air source connected to the end nut of the glass cover of the air inlet pipe (see Figure 4)
      • 11.8.4.5 Recheck the air flow rate of the volatile transport tube
      • 11.8.4.6 If the air flow rate is greater than 10 mL/min±0.2 mL/min, recheck the flow rate of the air source with a soap film flowmeter or digital handheld flowmeter
      • 11.8.4.7 If the air flow rate cannot be set to 10 mL/min±0.2 mL/min, contact the manufacturer
      • 11.8.4.8 If the air flow rate meets (the requirement), disconnect the soap film flowmeter from the volatile transport tube and remove the oil pipe stopper
      • 11.8.4.9 During the test procedure (the air flow rate) is allowed to fluctuate within the range of 10 mL/min±0.1 mL/min
• 12 Sample installation
  • 12.1 After the sample and catalyst are mixed in the sample bottle, check whether the mixture is uniform; if not uniform, continue stirring and check from time to time until uniform. Note: For high-viscosity or dark-colored samples, such as engine oil with a viscosity grade of 20W-40, achieving a uniform comparison is relatively difficult; it is required to observe the mixture under a (light) source to ensure complete mixing
  • 12.2 Clamp the sample bottle with a spring clip (as shown in 6.1.1.7 and 6.1.1.16)