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Digital Radiometers

Maximum calibration accuracy. All Spectroline radiometers are calibrated for the highest accuracy by pyroelectric methods that are directly traceable to NIST standards. A calibration certificate is supplied with every unit. The sensor heads are provided with special diffusers that ensure accurate cosine response. Since these sensors are configured with a low-offset transimpedance amplifier, their linearity is vastly superior to that of competitive units. This results in an unmatched overall accuracy of better than 5% on all meters.


bulletUnmatched overall accuracy of better than 5% - directly traceable to NIST standards
bulletPrecisely calibrated with pyroelectric radiometer for maximum accuracy
bulletNo sensitivity to infrared or other undesirable radiation due to use og high-quality interference filters in sensor construction
bulletAutozeroing feature
bulletVersatile - Ten models available to measure five different wavelength regions of ultraviolet and blue light
bulletExcellent linearity and cosine response
bulletReliable, solid-state circuitry
bulletCompact, durable and simple to operate
bulletBuilt-in battery-level indicator


Readout Unit

Irradiance Range
DMX-Series 0 - 19,990 W/cm2
DMH-Series 0 - 199.9 mW/cm2
(0 - 199,900 W/cm2)
DMX-Series 10 W/cm2
DMH-Series 0.1 mW/cm2
(100 W/cm2)
DMX-Series 4 1/2 digit, 7 segment, LED, 0.5 inch (12.7mm) high
DMH-Series 3 1/2 digit, 7 segment, LED, 0.5 inch (12.7mm) high

Conversion Rate
3 readings per second nominal

Overall Accuracy
Better than 5% with reference to NIST standards temperature coefficient 0.025%/C(0 to 50C)



Spectral Ranges
DM-254X and DM-254H 230 - 280 nanometers (nm)
DM-300X and DM-300H 280 - 320 nanometers (nm)
DM-365X and DM-365H 320 - 400 nanometers (nm)
DM-400X and DM-400H 420 - 480 nanometers (nm)

Temperature Coefficient
0.020%/C(0 to 50C)

Power Requirements
Four nonrechargeable "AA" size alkaline battery cells are included as standard.

Four rechargeable "AA" size NiCad battery cells and a battery recharger are available as an option.

Readout Unit
Length: 7-1/4 in. (18.4cm)
Width: 3-1/2 in. (8.9cm)
Thickness: 2 in. (5.1cm)
Weight: 1 lb. (0.45kg)

Length: 3 in. (7.6cm)
Width: 2 in. (5.1cm)
Thickness: 1/2 in. (1.3cm)
Weight: 1-1/4 oz. (35.4kg)

Sensor Cord Length
3ft. (91.4cm)


VDM-254X Short Wave Digital Radiometer
VDM-300X Medium Wave Digital Radiometer
VDM-365X Long Wave Digital Radiometer
VDM-450X Blue Light Digital Radiometer

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