ZPM process photometers for laser welding, material analysis and UVT
Opsytec process photometers measure the transmittance of solid and liquid samples at one fixed wavelength and report it in percent. Our range includes more than 30 wavelengths, so the photometer can be matched to the application – from UV transmittance (UVT) at 254 nm in water treatment and process control in laser welding of plastics to incoming goods and batch inspection in materials analysis. The optical density from the transmittance can be calculated in the radiometry calculator.
The key parameter here is UV transmittance (UVT). The UVT value at 254 nm describes how deeply UVC radiation penetrates a medium and feeds directly into the design and monitoring of UV disinfection systems: if the UVT drops, the same lamp power delivers a lower dose.
In laser welding of plastics, the transmittance of the upper joining partner determines how much laser power reaches the weld seam. Because our photometers measure at the process wavelength, the reading transfers directly to the process – unlike a transmittance value recorded at a different wavelength.
In material analysis, transmittance measurement serves incoming goods and batch inspection: films, glasses, filters and protective panes can be checked against a reference quickly and non-destructively.
For transmittance measurement in the UV the ZPM therefore works as a UV photometer: one fixed wavelength, one fixed beam path, one reading in percent – no spectrum that would have to be evaluated afterwards.
Process photometer ZPM
The process photometer ZPM measures the transmission of optical transparent materials like silica, glass, crystal, or plastics plates.
The influence of ambient light is minimized by using a modulation technique. This is of special importance for the measurement of scattering samples.
Yoke photometers measure at a fixed wavelength between 254 nm and 980 nm or with selectable wavelengths, for example, red (630 nm), green (520 nm), and blue (470 nm) for ZPM RGB.
Transmission data are steadily shown on the display. Measuring data can be read by a computer or PLC (optionally) manually or after being triggered.
The device under test can be adjusted and fixed using the optional alignment table. We also manufacture individual yoke photometers for scattering samples or custom sizes.
Applications of process photometer
- Detection of organic impurities, ozone, and turbidity in water
- Materials testing for laser beam welding
- Process control for glass, crystal, and plastic plates
- Monitoring of water treatment and wastewater
- Transmission measurements for water, wastewater, and industrial systems
- Measurement of chlorine concentration in fume gases
How a transmission measurement becomes a limit value for series release – reference part, process window and the difference between directed and total transmission – is covered on the application page laser processes and transmission testing.
Where the line runs between spectrophotometer, spectrometer and spectroradiometer, and which instrument solves which measuring task, is set out under spectrometers and spectroradiometers
Technical data ZPM process photometer for transmission measurements
| Measuring range | 0 to 100% transmission |
| Resolution | 0,1% |
| ADC | 24 bit |
| Calibration | 100% or reference filter |
| Sampling rate | 55 Hz to 0,6 Hz, adjustable |
| Averaging | 1–20, moving average |
| Display | graphical, 128 × 64 px |
| Dimensions, display unit | 185 × 251 × 100 mm |
| Dimensions, photometer | 160 × 110 × 30 mm |
| Weight | ~ 3 kg |
| Mains | 100–240 V, 50/60 Hz, 30 W |
| Connecting cable | 2 m, optionally up to 10 m |
| Lamp lifetime | typical 20.000 h |
| Operating temperature | 10 to 40 °C |
| Humidity | <80%, non-condensing |
| Output signal, opt. | 4–20 mA, 0–10 V |
| Relay contact, opt. | 2 × 250 V, 1 A |
| Interface | USB |
Available wavelengths of the ZPM process photometer
| Wavelength | Spectral range |
|---|---|
| 245 nm | UVC |
| 254 nm | UVC |
| 265 nm | UVC |
| 280 nm | UVC |
| 290 nm | UVB |
| 300 nm | UVB |
| 310 nm | UVB |
| 320 nm | UVA |
| 350 nm | UVA |
| 365 nm | UVA |
| 395 nm | VIS |
| 405 nm | VIS |
| 445 nm | VIS |
| 455 nm | VIS |
| 470 nm | VIS |
| 505 nm | VIS |
| 520 nm | VIS |
| 590 nm | VIS |
| 630 nm | VIS |
| 690 nm | VIS |
| 720 nm | VIS |
| 780 nm | VIS |
| 820 nm | NIR |
| 850 nm | NIR |
| 880 nm | NIR |
| 940 nm | NIR |
| 950 nm | NIR |
| 980 nm | NIR |
| standard illuminant 3500 K | VIS |
| 470, 520 and 630 nm at the same time | RGB |
The photometer is built for one of these wavelengths; the RGB version measures at 470, 520 and 630 nm at the same time.
Order numbers, scope of delivery, accessories and versions
| Version | Order number |
|---|---|
| Clamp photometer ZPM-XXX | 833000 |
| Clamp photometer ZPM-RGB | 833100 |
The ZPM-XXX measures at one wavelength, the ZPM-RGB at three at the same time. Please state the required wavelength with your order.
| Spectral range | Wavelengths |
|---|---|
| UVC | 245–280 nm |
| UVB | 290–310 nm |
| UVA | 320–365 nm |
| VIS | 395–780 nm and standard illuminant 3500 K |
| NIR | 820–980 nm |
| RGB | 470, 520 and 630 nm at the same time |
The photometer is built for one of these wavelengths; the RGB version measures at 470, 520 and 630 nm at the same time. Which wavelengths are available in detail is listed in the accordion Available wavelengths of the ZPM process photometer above.
| Option | Order number |
|---|---|
| PLC output 0–10 V | 833003 |
| PLC output 4–20 mA | 833004 |
| Switching contacts, adjustable | 833005 |
| Clamp detection | 833000e |
| Double-beam option | 833000d |
| Cable, per further metre | 833000m |
The options are ordered together with the photometer; the connecting cable is 2 m long, on request up to 10 m.
| Designation | Order number |
|---|---|
| Alignment table | 833002 |
| Component holder | 750000 |
| Base plate | 833006 |
| Transmission reference | 833010 |
| Laser protection (class 1) | 760000 |
