A Photometry: Instrument Tab (Measurement type: Wavelength, Ratio)
F.3.2A Photometry: Instrument Tab (Measurement type: Wavelength, Ratio)
Parameter Name
Setting Range
Wavelength 1 to 6
Model Input range
U-1900/2900/2910/
190.00 to 1100.00 nm
3900/3900H/5100 U-4100/UH4150
Delay
0 to 3600 s
Lamp change
Auto, D2 only, WI only
mode (for other than U-5100)
Lamp change
325.00 to 370.00 nm
wavelength (for other than U-5100)
WI Lamp (for
On, Off
other than U-5100)
D2 lamp (for other
On, Off
than U-5100) Slit width (nm)
Model U-3900/3900H
Input range
U-1900
: Fixed at 4 nm
U-2900/2910 : Fixed at 1.5 nm U-5100
: Fixed at 5 nm
U-4100/UH4150 : Select a slit width in the ultraviolet/visible region. It is recommended to fix the slit width for ordinary measurement.
Auto : The slit width is automatically controlled according to the optical energy level under a specified photomultiplier voltage. Concretely, the slit width is widened at a low optical energy level and narrowed at a high optical energy level. In other words, this is a function depending mainly on the S/N ratio (signal-to-noise ratio). In this mode, the slit width automatically changes in a range of about 0.01 to 14 nm. This mode cannot be set simultaneously with PMT mode “Auto”.
Parameter Name
Setting Range
Slit width (nm)
Fixed : The slit width is selectable in a range of 0.1 to 8.0 nm in 0.01 (0.02) nm steps. (The parenthesized step corresponds to slit width 2.4 nm or wider.)
PMT mode (with
Auto, Fixed
U-3900/3900H/
When “Fixed” is selected, the photomultiplier voltage
is settable.
PMT voltage (with
0 to 1000 V
U-3900/3900H/ 4100/UH4150)
Integration time
0.5 to 10.0 s
(with U- 3900/3900H
Replicates (STD)
0 to 20
Replicates (UNK)
0 to 20 Effective when “Use Sample Table” on the General
tab page is turned ON. Statistics ON, OFF Statistics Number
2 to 4000 Effective when “Statistics” is turned ON.
NOTE: If “Replicates (UNK)” ≥ 2, this parameter is settable in a range of
1 to 4000.
Path correct
ON, OFF When turned ON (checked), cell length correction is
effective.
Path Length
0.1 to 100.0 mm
Parameter Name Setting Range
Attenuation (with The beam attenuator is inserted on the reference U-4100/UH4150)
side. Set the attenuation ratio of the attenuator. This setting is usable for a sample whose absorbance and transmittance/reflectance are 4 Abs or more and 0.1%T or less, respectively. For usage, select the Attenuation command from the Spectrophotometer menu after baseline measurement. Then, carry out sample measurement.
None 1/10 1/100
Detector change A function for automatically correcting the difference correct (with
in photometric value between the detector U-4100/UH4150)
changeover points in the near infrared and visible regions.
On Off
Detector change Set up a wavelength for changeover between the wavelength (with
detectors for the ultraviolet/visible and near infrared U-4100/UH4150)
regions. Input range: 700.0 to 900.0 nm
Scan speed (with Set up a scan speed in the near infrared region. U-4100/UH4150)
0.75 nm/min
Parameter Name
Setting Range
Slit width (with
Set up a slit width in the near infrared region.
U-4100/UH4150)
Fixed : Input range: 0.1 to 20.0 nm in steps of
0.1 nm
Auto : The slit width is automatically controlled according to the optical energy level. This function is intended to keep the S/N ratio (signal-to-noise ratio) constant in the measuring wavelength range as far as possible. In this mode, the slit width automatically changes in a range of about
0.1 to 36 nm. This mode cannot be set simultaneously with Light control mode “Auto”.
PbS Gain (with
Specify a sensitivity level of the detector for the near
U-4100/UH4150)
infrared region. The PbS sensitivity is settable at four levels. Level 1 is used as a reference. Levels 2, 3 and 4 are 2, 4 and 8 times as high as level 1, i.e., the sensitivity rises in the order of 1, 2, 4 and 8 (times). For high resolution measurement in the near infrared region, use a higher sensitivity (PbS sensitivity level 3 or 4). However, use of ahigh sensitivity inevitably entails an increase in noise level. Therefore, PbS sensitivity level 2 is generally recommended. Use Pbs sensitivity level 1 for measuring quite a flat spectrum with no large absorbance change or checking spectral features alone with minimum noise.
Light control mode
A mode for controlling the light quantity in the near
(with U-4100/
infrared region.
UH4150)
Fixed : Used for ordinary measurement. Auto : Used when measurement cannot be
performed with the slit width fixed because the light quantity in the near infrared region is excessive.