Highly Sensitive Silica Monitor SLIA-300


Satisfies the customer's demands for measuring the ultra-low density of silica at the finest sensitivity of 0.01 µg/L (0.01 ppb)
The ultra-pure water that is used in the semiconductor production processes can be further purified by using an ion-exchange resin. Capturing the silica that is dissolved from this ion-exchange resin as quickly as possible can control the ultra-pure water quality, which is important during the production processes.
HORIBA Advanced Techno has developed and employed a new "long light path length measurement cell" to enable highly sensitive measurement of ultra-low density silica and also realized a compact desktop model to improve the usability.
With a broad range of standard features such as self-diagnosis and new performance improvements such as high-speed response and high sensitivity, this product provides enhanced support for the pure water processes in the production of semiconductors.


  • High Sensitivity and High Reproducibility
    A long light path of approx. 1 m is secured by applying fiber optic technologies. This realizes high sensitivity that responds to ultra-low density. This product ensures the reproducible accuracy of the full scale ±2% within the range from 0 to 2 µg/L during high-speed 5-minute measurement.
    Highly Sensitive
  • Desktop Model Compact Design
    The flexible structure of the "long light path length measurement cell" also realizes a revolutionary compact design. This desktop model is available for various installation conditions such as small spaces.   
    Desktop Model
  • Reduced Consumption of Reagent to 1/5
    To reduce the consumption of reagent to 1/5 of the previous amount, the reaction cell has been improved and separated from the measurement cell. Also, the measurement cell has been changed to a tube type. Employing the "long light path length measurement cell" can reduce the running cost for reagents drastically.
     low running costs 
  • Reduced Consumption of Reagent by More Than Half
    Reduced the consumption of not only the reagent but also the sample water.
    By employing the "long light path length measurement cell," the consumption of expensive pure water (used as sample water) is reduced by 60%. The silica monitor from HORIBA Advanced Techno contributes to reduce the on-site costs.    
  • Self-Diagnosis Function That Monitors for Operation Errors
    Performs self-diagnosis for operation errors such as sample water and/or reagent injection, calibration error, temperature monitoring in a cell, and light source error. When an error is found, a warning lamp is lit and a text message is displayed.
  • Automatic Calibration to Realize Superior Maintainability
    Zero calibration is always performed automatically to check for transmitted light and to calibrate the turbidity.
  • Up to Six-Point Measurement Allowed (Optional)
    Up to six measurement points can be set. A single unit can be used for multi-point measurement.
  • Semi-permanent Light Source Employed: No Replacement Necessary
    A monochromatic semiconductor light source, which provides a steady light volume and long life, is employed. It can be used as semi-permanent light source.

Long Light Path Length Measurement Cell: Detects 0.01 µg/L at Minimum

The measurement cell has a double structure in which a light permeable fluorocarbon resin tube runs through a stainless steel pipe. The light coming in from one side of the pipe is repeatedly reflected in the pipe due to the difference of the refractive index between the fluorocarbon tube and the ambient air before reaching the other side.
This light transmission mechanism is an application of the optical fiber's high efficiency and low blockage principle, which realizes improved detection sensitivity and high reproducibility. (Patent pending)

silica monitor slia-300

This long light path length cell employs a flexible tube structure, enabling a small-footprint design. By storing the long cell of approx. 1 m in a desktop compact body, a small unit that is 1/8 the size of the previous model has been realized.
Also, the tube structure of the cell has a big advantage for reducing running costs: it reduces the consumption of color reagent and sample water to 1/5 and 1/2 of the previous amounts, respectively.

Manufactured by HORIBA Advanced Techno




Measurement method

Molybdic blue absorptiometry

Measurement range

0 to 2 / 0 to 20 µg/L, or 0 to 5 / 0 to 50 µg/L (please specify when placing an order)

Measurement time

5 minutes

Measurement points

1 to 6 points (please specify when placing an order)


±2% of full scale

Calibration function

Standard fluid calibration

Compensation function

Blank compensation
Metage line compensation (Specific to each line)

Reagent used

· Reagent A: sulfuric acid + ammonium molybdate
· Reagent B: oxalic acid
· Reagent C: L (+) - ascorbic acid

Reagent replacement interval

One week (according to the recommended period of our company)


100 to 240 V AC 50/60 Hz

Max. power consumption

Approx. 600 VA

Installation condition

Indoor, Ambient temperature 10 to 35°C, Humidity 85% or lower

Sample water condition

· Water temperature: 15 to 35°C
· Supplied flow rate: 250 to 300 mL/min (must be adjustable)
· Pressure: 0.1 to 0.5 MPa

Outside dimensions

580 (W) x 375 (H) x 500 (D) mm


One-point measurement: approx. 41 kg (plus 1 kg for an additional measurement point)

External I/O

Density output

4 to 20 mA DC / 0 to 16 mA DC / 0 to 1 V DC (to be specified at order)

Contact output

· Common to all lines:
During measurement, synchronous signals, alarms (batch), heaters, power off, calibration signals 1 and 2, density upper limit warning, or sample water off.
· Specific to each line:
Measurement range, density upper limit warning, or sample water off (the density limit warning or the sample water off batch or respective line alarm should be specified when placing an order. The alarm contents should be also selected when placing the order.)

Contact input

· Common to all lines:Calibration start, measurement start, cost-efficient operation, line selection, measurement low range, measurement high range

Serial I/O


Applicable standard

CE mark, FCC Part 15


Sample water heating unit, standard fluid supply unit, reagent blending tools