Zwei Küvetten können äußerlich identisch sein und sich im Gerät völlig unterschiedlich verhalten. Der Unterschied liegt im Aufbau. Das Herstellungsverfahren setzt die Obergrenze für drei Dinge, die wirklich zählen: Betriebstemperatur, Chemikalienbeständigkeit und Transmission. Diese Anleitung erklärt die drei von uns gefertigten Bauweisen und die Auswahl.
Quartz itself is extraordinarily resistant — it survives temperatures and chemicals that destroy any adhesive. So the limiting factor in a cuvette is almost never the quartz; it is the joint. A glued cell inherits the adhesive's limits (roughly 100 °C, neutral pH). A fused or optical-contact cell has no adhesive in the optical path, so it inherits the quartz's limits instead — several hundred degrees and essentially the full chemical range.
That single distinction explains most of the price difference between an entry-level cell and a premium one.
Polished quartz plates are bonded together with an optical adhesive. It is the most economical method and supports the widest range of formats, which is why it dominates teaching labs and routine aqueous work.
Quartz powder is fused at high temperature into a single monolithic body. There is no adhesive anywhere in the cell, so the finished cell is chemically and thermally limited by the quartz rather than by a glue line.
Optical surfaces are joined by optical contact and formed as one piece, with no adhesive and no powder-sintering boundary. This is our highest-precision construction, and the one we supply where the specification calls for German-original-equivalent optical performance.
| Glued (cemented) | Powder fusion | Optical contact molding | |
|---|---|---|---|
| Transmittance | >80% | >83% | >83% |
| Max operating temp | <100 °C | <600 °C | up to 1200 °C |
| Chemical resistance | Neutral samples only | Acid, alkali, organic solvents | Acid, alkali, organic, high temp |
| Construction | Adhesive-bonded plates | Fused monolithic body | Optical-contact one-piece |
| Optical quality | Standard | High | Premium (comparable to German original imports) |
| Relative cost | Lowest | Mid | Highest |
| Best for | Routine aqueous UV-Vis, teaching labs | Harsh chemistry, heated samples | Deep UV, fluorescence, high temperature |
Work down this list and stop at the first line that matches:
Fabrication method and quartz grade are independent choices. Grade sets the transmission window (JGS1 for deep UV from ~200 nm, JGS2 for general UV-Vis, JGS3 for IR); construction sets the chemical and thermal limits. A premium optical-contact cell built from the wrong grade still will not transmit at your wavelength — and a JGS1 cell with glued construction still cannot take organic solvent.
Both are covered in the UV cut-off and grade guide.
Glued cells need short, cool ultrasonic cycles and no autoclaving. Fused and optical-contact cells tolerate far more aggressive treatment, including strong solvents and high-temperature drying. Getting this wrong is one of the most common causes of premature cell failure — the full procedure is in the cleaning protocol, and solvent limits are tabulated in the solvent compatibility guide.
Related: UV Cut-Off & Grades · Cleaning Protocol · Solvent Compatibility · Cuvette Care Guide · Fused Silica vs Quartz · Path Length Guide