TML (Total Mass Loss) testing is an essential outgassing evaluation required for materials used in spacecraft, satellites, and other high-vacuum applications, and understanding TML testing prices helps engineers budget accurately for material qualification programs. This guide explains typical TML testing costs, the key factors that influence laboratory quotes, applicable standards such as ASTM E595, and answers to frequently asked pricing questions.
Technical Overview
TML (Total Mass Loss) testing measures the amount of mass a material loses when exposed to a simulated space vacuum environment. During the test, specimens are heated to 125°C for 24 hours under a vacuum of 5×10⁻⁵ torr or lower, while volatile effluents condense on a collector plate maintained at 25°C. The percentage of mass lost by the specimen is reported as TML, and the mass of condensed volatiles on the collector is reported as CVCM (Collected Volatile Condensable Materials).
This test is widely used in the aerospace industry because outgassed molecular contamination can degrade optical surfaces, sensors, solar cells, and other sensitive spacecraft components. Space agencies such as NASA and ESA generally require spacecraft materials to meet acceptance criteria of TML below 1.0% and CVCM below 0.10% in accordance with ASTM E595. TML testing price is one of the most common inquiries from procurement and quality teams when planning material screening budgets.
TML Testing Price Overview
The price of a TML test varies depending on the laboratory, geographic region, and project requirements. As a general reference, a single-sample TML and CVCM test performed to ASTM E595 typically ranges from approximately USD 200 to USD 600 per sample. In the Chinese testing market, quotations commonly fall in the range of RMB 1,500 to RMB 4,000 per sample group, depending on the laboratory's accreditations and turnaround commitments.
Factors That Influence TML Testing Cost
- Number of samples: laboratories typically offer tiered pricing, with discounts of 10% to 30% for batch submissions of five or more specimens.
- Test scope: a combined TML, CVCM, and WVR (Water Vapor Regained) package costs more than TML alone.
- Standard required: testing to ECSS-Q-ST-70-02 may be quoted higher than ASTM E595 due to additional documentation requirements.
- Sample preparation: specimens that must be cured, dried, machined, or subdivided before testing incur extra preparation fees.
- Turnaround time: standard turnaround is usually 5 to 10 working days; expedited 2 to 3 day service can add a 30% to 100% surcharge.
- Report requirements: notarized, CNAS-stamped, or bilingual reports may carry additional administrative charges.
Ways to Control Testing Budget
- Consolidate multiple materials into a single test campaign to qualify for batch pricing.
- Submit pre-conditioned specimens cut to the required dimensions to avoid preparation fees.
- Verify whether WVR testing is contractually required before ordering the full parameter package.
- Request written quotations from at least two to three accredited laboratories to compare scope and price.
Testing Samples
Polymer and Plastic Materials
Engineering plastics such as PEEK, PTFE, polyimide, polycarbonate, and nylon are commonly submitted because polymeric materials are the principal source of spacecraft outgassing. Specimens are typically prepared in pieces of approximately 150 to 300 mg each, with three specimens recommended per material for statistical confidence.
Elastomers and Rubbers
O-rings, gaskets, diaphragms, and silicone or fluorocarbon rubber compounds are tested because seal materials experience significant mass loss at elevated temperature and can release silicone-based contaminants that are harmful to optics.
Adhesives, Sealants, and Potting Compounds
Structural adhesives, conformal coatings, encapsulants, and room-temperature vulcanizing (RTV) silicones must be fully cured before testing. Incomplete cure is one of the leading causes of outgassing test failures.
Coatings, Paints, and Films
Thermal control coatings, black anodize sealants, metallized polymer films, and pressure-sensitive adhesive tapes are screened to verify they meet contamination control limits before integration onto flight hardware.
Composite and Insulation Materials
Carbon fiber composites, honeycomb panels, multilayer insulation (MLI) blankets, foams, and cable insulations are also submitted, since even seemingly inert materials can release adsorbed moisture and processing residues.
Testing Items
A complete outgassing evaluation per ASTM E595 comprises three measured parameters, and TML testing price generally depends on how many of these are included in the order:
- TML (Total Mass Loss): the percentage of total specimen mass lost after 24 hours at 125°C in vacuum. Acceptance limit is typically 1.0%.
- CVCM (Collected Volatile Condensable Materials): the mass of volatiles that condense on a 25°C collector plate, expressed as a percentage of the original specimen mass. Acceptance limit is typically 0.10%.
- WVR (Water Vapor Regained): the mass regained by the specimen after 24 hours of exposure to 50% relative humidity at ambient temperature, indicating how much of the TML was recoverable water.
Testing Methods
Testing is performed in an apparatus consisting of a heated sample chamber, copper collector plates, and a vacuum system capable of maintaining pressure below 5×10⁻⁵ torr. The standard workflow is as follows:
- Specimens are cleaned, weighed on a microbalance, and loaded into individual compartments of the sample bar.
- The assembly is placed in the vacuum chamber, and specimens are held at 125°C for 24 hours while the collector plate remains at 25°C.
- After repressurization with dry nitrogen or air, specimens and collectors are reweighed to calculate TML and CVCM.
- For WVR, specimens are exposed to controlled humidity for 24 hours and weighed a third time.
The primary reference standards include ASTM E595 (Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from Outgassing in Space Environment Simulation) and ECSS-Q-ST-70-02 (thermal vacuum outgassing test for spacecraft materials). When requesting a quotation, always confirm which standard your program requires, as it affects both the technical protocol and the final price.
Applications
TML testing services are purchased by organizations across several industries, and understanding these use cases helps clarify why pricing structures differ between projects:
- Spacecraft and satellite material selection and screening during design phases.
- Verification of flight hardware compliance with NASA, ESA, and national aerospace contamination control specifications.
- Qualification of materials used near optical payloads, sensors, telescopes, and infrared detectors where molecular film deposition is unacceptable.
- Evaluation of paints, coatings, and thermal control surfaces for outgassing stability.
- Quality control for suppliers of adhesives, potting compounds, and cable materials to the space sector.
- Contamination assessment for ultra-high vacuum equipment used in semiconductor manufacturing and particle accelerators.
FAQ
How much does TML testing cost? Typical pricing ranges from USD 200 to USD 600 per sample for a combined TML and CVCM test to ASTM E595, with regional variations. Batch submissions, additional parameters, and expedited turnaround all affect the final quotation, so laboratories recommend requesting a formal written quote based on your material list.
How long does TML testing take? The 24-hour vacuum exposure is fixed by the standard, so end-to-end service time is usually 5 to 10 working days including sample handling, weighing, and report preparation. Rush services of 2 to 3 days are available at most laboratories for an additional fee.
How many specimens are required? Most laboratories request a minimum of 50 grams of bulk material or prepared specimens of approximately 150 to 300 mg each, and three specimens per material are recommended to obtain a reliable average result.
What are the pass criteria? The widely accepted limits are TML ≤ 1.0% and CVCM ≤ 0.10%. Materials exceeding these values may still be accepted with additional justification if they are located away from sensitive surfaces, but this requires program-level approval.
Does the quoted price include WVR testing? Not always. WVR is an optional measurement in ASTM E595, so confirm in writing whether your quotation covers TML only, TML plus CVCM, or the full three-parameter package before placing the order.