Yoke product guide

The Yoke product guide is the document we send when a buyer asks what we make, rather than what one particular model does. It is an eight-page overview of the six instrument lines we build in Shanghai, with three representative models per line and the one or two features that separate them. Full model lists and specification tables stay on the product pages of this site, so the file stays short enough to read in one sitting.

That breadth is the point. Most inquiries arrive with a method and a sample matrix, not a model number: a laboratory that has to report copper at 0.5 mg/L in effluent, or a teaching department that needs thirty students to run the same assay inside a two-hour practical. The guide gives you the shape of the range before narrowing down, instead of starting from whichever model happened to surface first in a search.

What the guide covers

• Spectrophotometers — 30 series. UV-Vis from single-beam teaching instruments to double-beam platforms covering 190–1100 nm, plus atomic absorption, fluorescence, flame photometry and microvolume instruments for nucleic-acid work.
• Water analysis — 54 series. Bench and portable multi-parameter analyzers, pH, conductivity and dissolved-oxygen meters, turbidity and color meters, potentiometric and Karl Fischer titrators, COD and BOD analyzers, and the digestion blocks that go with them.
• Chromatographs — 4 series. Gas chromatographs with either manual gas control or full electronic pressure control, and dual-channel ion chromatographs including a fully PEEK flow path for high-pH eluents.
• Balances — 9 series. Analytical and precision balances from 0.01 mg readability, plus halogen moisture analyzers for loss-on-drying work.
• Melting point meters — 2 series. Automatic capillary instruments with real-time curve output, one of them adding live video of the capillary.
• Polarimeters — 1 series. Optical rotation and specific rotation with Peltier temperature control. This line is not in the current PDF edition; the model and its specification table are on the polarimeter page.

How to shortlist a model from the guide

1. Fix the measurement first. Decide the parameter, the expected concentration range and the required uncertainty. A method that reports copper at 0.5 mg/L and one that reports it at 5 µg/L sit in different chapters: flame atomic absorption for the first, graphite furnace for the second.
2. Match the optical or separation performance to the method. For UV-Vis, the controlling figures are spectral bandwidth, wavelength accuracy and stray light, not the size of the screen. For chromatography, it is the detection limit, the linear range and the pressure the column expects.
3. Count what the bench actually has to handle. Samples per day, whether results must be exported to a LIMS, whether the instrument leaves the laboratory. A portable analyzer with a six-hour battery is the right answer to a sampling round and the wrong answer to a bench that runs two hundred tests a day.
4. Read the accessory column before asking for a price. Autosamplers, printers, sample cells, columns and gas generators are frequently the difference between two quotations that look far apart.

Reading a specification table

A specification table is only useful if you know which rows decide the result. Five of them do most of the work:

• Wavelength accuracy and repeatability — where the peak actually lands, and whether it lands in the same place twice. Quoted against a reference: the absorption peaks of a holmium oxide filter, or the emission line of a deuterium lamp at 656.1 nm. These are two different kinds of standard, an absorption peak and an emission line, so a figure without its reference wavelength says very little.
• Stray light — radiation that reaches the detector outside the selected spectral band, from scattering, higher-order diffraction or internal reflection. It puts a floor under measurable transmittance, and therefore a ceiling on absorbance: at 0.03%T the theoretical ceiling is about 3.5 A, and where the usable range ends below it depends on the wavelength, the reference method and the error you can accept. Treat the figure as a way to compare instruments, not as a guarantee to a given absorbance.
• Photometric accuracy and repeatability — absolute and short-term error in absorbance. For a quantitative assay, repeatability usually matters more than accuracy, because a bias can be corrected by calibration and scatter cannot.
• Detection limit and characteristic concentration — the two figures that decide whether a trace method is feasible. Characteristic concentration tells you the sensitivity per unit concentration; the detection limit tells you the floor.
• Temperature control accuracy and stability — the row that gets skipped and then explains why two laboratories cannot reproduce each other’s melting point or refractive result.

What the guide does not include

The guide is an overview, not a quotation. It deliberately omits four things, all of which depend on the destination and the configuration:

• Prices. Instrument pricing moves with configuration, volume and shipping terms. Any figure printed in a PDF would be wrong by the time it reached you.
• Lead times. These depend on the model, the accessory set and the shipping lane at the time of order.
• Certification for your market. CE documentation is available for the UV-Vis and water-analysis lines; other markets and other product lines need to be checked against the specific directive before the order, not after.
• Custom and OEM configurations. Enclosures, labeling, voltage and software localisation are quoted case by case.

When to ask for a configuration review

Three situations justify sending the method rather than the model number. When the sample matrix is unusual — high salt, high organic load, suspended solids — because the matrix decides the preparation step and often the detector. When the result has to be defensible to an auditor, because then the documentation set matters as much as the instrument. And when the laboratory is being equipped as a whole rather than extended by one unit, because shared accessories, sample flow and bench space are cheaper to plan once than to retrofit.

Send the method, the sample matrix and the annual sample count. We will come back with the model, the accessory list and the documents that go with it, rather than a catalog page and a price.

Address printed in the file. The PDF carries a previous company address. For the address used on orders, invoices and shipping documents, see the contact page.

Where to go next

• Browse the full product catalog — filter by instrument line and open the specification table for any model.
• Spectrophotometers, water analysis, chromatography, balances, melting point meters and polarimeters — the six lines in detail.
• Applications — method notes grouped by industry, from drinking water to pharmaceutical QC.
• Contact the application team — send a method for a configuration review.