Praying Mantis™ Diffuse Reflection Accessory

The Praying Mantis™ was the first generally available diffuse reflection (DRIFTS) attachment and remains the forerunner in the field.

It is a highly efficient diffuse collection system that minimizes the detection of the specular component. Ellipsoids pivot to provide easy access to the sampling area and incorporates to 6:1, 90° off-axis ellipsoids which form a highly efficient diffuse reflection illumination and collection system. This unique configuration deflects the specular reflectance away from the collecting ellipsoid, minimizing the associated spectral distortions.

The Praying Mantis™ also can be configured to study materials and reactions in controlled environments with the appropriate diffuse reflectance reaction chamber.

Praying Mantis™ applications include easy and reliable diffuse reflection analysis of solids and powders by FT-IR and UV-VIS spectroscopy and analysis of catalysts and other powders in a temperature and/or pressure controlled environment.

Praying Mantis™
Diffuse reflection accessory
Model No.
DRP-XXX
Price
N/A
Diffuse Reflection Catalysis Package, 110V
Kit with Praying Mantis, Reaction Chamber, Controller, etc.
Model No.
DRK-3-XXX
Price
N/A
Diffuse Reflection Catalysis Package, 220V
Kit with Praying Mantis, Reaction Chamber, Controller, etc.
Model No.
DRK-4-XXX
Price
N/A
NOTE: A Model No. ending in "XXX" denotes spectrometer code.

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Features
  • Highly efficient collection system.
  • Minimizes the detection of the specular component.
  • Ellipsoids pivot to provide easy access to the sampling area.
  • Allows easy attachment of reaction chambers.
  • Several models offered for compatibility with a wide range of FTIR and UV-VIS spectrometers.
  • Harrick's exclusive PermaPerge™ allows rapid exchange with minimal interruption of the system purge.
  • Optional references for FTIR and UV-VIS studies.
Includes
  • Praying Mantis:
    • Cart with two mounted alignment mirrors.
    • 10mm diameter diffuse reflectance sampling cup (0.25ml volume).
    • 3mm diameter adjustable microsampling cup (0.03ml volume) with funnel.
    • Mating hardware for the specified FTIR or UV-VIS spectrometer.
  • Praying Mantis Kit:
    • Praying Mantis.
    • High Temperature, Low Pressure Reaction Chamber with SiO2 or ZnSe windows.
    • Temperature Controller with USB to RS-485 adapter for computer control.
    • Sampling Tools: spatula, KBr powder, finger cots, mortar and pestle.
 
Model No. Product Description Price
CHC-CHA-3 Low Temp. Reaction Chamber (FTIR)

Praying Mantis™ diffuse reflection environmental chamber, 24V

N/A
CHC-VUV-3 Low Temp. Reaction Chamber (UV-Vis-NIR)

Praying Mantis™ diffuse reflection environmental chamber, 24V

N/A
HVC-DRM-5 High Temp. Reaction Chamber (FTIR, ZnSe)

Praying Mantis diffuse reflection environmental chamber, 24V

N/A
HVC-DRP-5 High Temp. Reaction Chamber (FTIR, KBr)

Praying Mantis diffuse reflection environmental chamber, 24V

N/A
HVC-VUV-5 High Temp. Reaction Chamber (UV-Vis-NIR)

Praying Mantis diffuse reflection environmental chamber, 24V

N/A
 
Model No. Product Description Price
DRP-ASC Ambient Chamber (FTIR) for Praying Mantis Air-tight enclosure for diffuse reflectance N/A
DRP-ASC-VUV Ambient Chamber (UV-Vis-NIR) for Praying Mantis Air-tight enclosure for diffuse reflectance N/A
DRP-S10 Sample Cup for Praying Mantis 10 mm dia. 316 stainless steel sample cup assembly N/A
DRP-SAP Sampling Accessory Kit for Praying Mantis Set with sample cups and aligment fixture N/A
DRP-STK Diffuse Reflection Sampling Tools Mortar, pestle, KBr powder, spatula, finger cots N/A
DRP-SX3 Microsample Cup and Funnel for Praying Mantis 3 mm dia. 316 stainless steel sample cup assembly N/A
KIT-MAP Mortar and Pestle Alumina (99.5%); 7 ml capacity N/A
Reference & Mirrors
Model No. Product Price
DRP-ALN Alignment Fixture for Praying Mantis $377.00
DRP-SPR Spectralon Reference for Praying Mantis $125.00
Other
Model No. Product Price
KIT-SCP Spatula/Scoopula $17.00
Praying Mantis Diffuse Reflection Accessory

The Praying Mantis™ was the first generally available diffuse reflection accessory (DRA) and remains the forerunner in the field today. It is ideal for reliable diffuse reflectance studies of powders and other rough surface solid samples.

Figure 1. Interior View of the DRP.

The typical optical configuration of the Praying Mantis Diffuse Reflectance Attachments is shown in Fig. 1. The DRA incorporates two 6:1 90° off-axis ellipsoidal mirrors. One ellipsoid focuses the incident beam on the sample while the second collects the diffusely reflected radiation from the sample. Both ellipsoidal mirrors are tilted forward so the diffusely reflected radiation is collected at an azimuthal angle of 120°. This deflects the specularly reflected component behind the collection ellipsoid, minimizing the intensity of restrahlen bands caused by the specularly reflected light. Most other commercially available attachments collect the diffusely reflected light at 180°, where the restrahlen bands have maximum intensity. This optical geometry permits collection of up to 20% of all the diffusely reflected radiation, making the DRA quite practical for routine measurements.

The Praying Mantis can be used to examine powders and small solid samples. The sample is placed in one of the diffuse reflectance supplied sampling cups on the Praying Mantis sampling stage. The height of the stage can then be adjusted for optimal performance. The micrometer-style height adjustment allows for accurate and reproducible positioning of the sample. For easy access to the sampling area, the Praying Mantis features the ability to flip its illumination and collection ellipsoids away from optical plane of the attachment.The Praying Mantis also features PermaPurge and hence is enclosed in a purgeable box for rapid sample exchange with minimal interruption of the purge. This eliminates interference from water and carbon-dioxide bands in the infrared spectra.

The Praying Mantis is ideal for studying samples in a controlled environment and several optional environmental chambers are offered. Our Ambient Sample Chamber is designed for analysis of air-sensitive samples. The samples can be loaded in a glove box or similar enclosed environment. The chamber can then be sealed, removed from the glove box, and inserted in the Praying Mantis for diffuse reflectance analysis. This Ambient Sample Chamber features a removable stainless steel dome with two infrared or UV-Vis windows and a glass observation window.

Two reaction chambers (see separate data sheet) are
also available. These reaction chambers are designed for operation in static or flow conditions. Our Low Temperature
Chamber
is designed for operation from -150ºC to 600ºC (under vacuum) and from high vacuum (133 µPa or 10-6 torr) to 133 kPa (1 ktorr). Our High Temperature, Low Pressure Chamber operates at temperature up to 910ºC (under vacuum) and from pressures of 133 µPa (10-6  torr) to 133 kPa (1 ktorr) with KBr windows or 1.5 MPa (11.3 ktorr) with ZnSe or UV-grade SiO2 windows. With its optional High Pressure Dome, this chamber can withstand pressures up to 3.44MPa (25.8 ktorr). This chamber, with ZnSe infrared or UV-grade SiO2 windows, can be purchased as part of a kit including the Praying Mantis™ and Temperature Controller.

Representative DRIFTS spectra recorded with the Praying Mantis are shown here in Figures 2 and 3. Note that Figure 3 was recorded using the DRA with its HVC reaction chamber.

Figure 2 (left). Diffuse Reflection of Chalk.

Figure 3 (right). Diffuse Reflection of Wyodak Coal (A) after 24hrs of oxidation at 2.4KPa at 393deg; C, (B) dried unoxidized samples and (C) the difference spectrum (A-B).