Applications
- Faecal Indicator (FI) monitoring
- Assessment of bathing & shellfish waters
- Filter bed management
- Groundwater quality monitoring
- Plant loading assessments from river abstractions
Features
- Real-time indication of bacteria levels (in µg/l of Tryptophan)
- Automated data logging (2Gbyte storage capacity)
- 4 – 20mA output for data export in real-time
- Relay for audible alarm or control valves
- In-line flow-through operation with standard pipe fittings
- High sensitivity
Introduction
CTG’s BACTI-Station and BACTI-Station Pro systems allow laboratory managers, process scientists and engineers to assess real-time levels of bacteria in water systems. This is achieved by detecting UV Tryptophan fluorescence, which has been shown to correlate with bacterial levels.
The BACTI-Station comprises of a CTG UviLux fluorometer and a Watchkeeper wall mounted data display and logger. CTG’s UviLux fluorometers detect UV fluorescence with industry- leading sensitivity and selectivity and have been optimised for minimal interference from water turbidity. Data is displayed on the Watchkeeper’s colour touchscreen and is logged internally. Up to three 4 - 20mA outputs are provided for data transmission.
What is the difference between BACTI-Station & BACTI-Station Pro?
The BACTI-Station comprises a single CTG UviLux Tryptophan fluorometer and a Watchkeeper wall mounted data display and logger. The BACTI-Station Pro includes an additional UviLux sensor for discriminating Tryptophan fluorescence from Coloured Dissolved Organic Matter (CDOM). This is particularly useful when CDOM background levels are high or when correlating Tryptophan concentrations across a wide range of locations where background CDOM levels are varying.
How does it work?
CTG’s BACTI-Station and BACTI-Station Pro detect UV fluorescence from amino acids and organic matter associated with the presence of bacteria. These compounds absorb UV light and re-emit a fraction of this energy as fluorescence at longer wavelengths. Fluorescence intensity is directly proportional to concentration. The technique is widely recognised as one of the most sensitive detection methods available.
Tryptophan is an essential amino acid in the human diet and is the main component of protein fluorescence. Recent work has indicated that Tryptophan fluorescence can be used to assess bacterial levels, which in environmental waters will often arise from faecal/sewage contamination. Therefore, high levels of Tryptophan fluorescence will alert to when sewage impacts on water quality, for example when monitoring Bathing Waters.

Fluorescence map of an environmental water sample spiked with
Tryptophan, indicating BACTI-Station measurement window
Configuration
The BACTI-Station and BACTI- Station Pro have been designed for outdoor operation, with the UviLux fluorometers either fitted within a water trough or mounted in flow-through manifolds for in-line operation. A single cable connects the UviLux fluorometers to the Watchkeeper display and logger unit, which is powered from a 24 Vdc supply. Signal inputs are presented on the screen and up to three 4 – 20 mA signals can be accessed for data system networking. Audible alarms or control valves can be fitted and programmed to alert or activate when signals exceed user-set thresholds. Data is recorded onto a 2 Gbyte memory card. Data can be download via a USB cable, or by removal of the memory card.
Specification
UviLux Fluorometer
Size |
Ø70 x 150 mm
|
Weight |
800 g
|
Pressure Rating |
60 bar
|
UviLux Performance
|
Tryptophan |
CDOM
|
Sensitivity (QSU) |
0.01
|
0.01
|
Calibrated range (QSU) |
600
|
600
|
Example compound: sensitivity – range (ppb) |
Tryptophan: 0.02–1200 |
PTSA:* 0.02–900 |
*PTSA is pyrene tetrasulphonic acid
BACTI-Station, single UviLux fluorometer with Flow Manifold
Size |
Ø130 x 200 mm
|
Weight |
2.5 kg
|
Fluid connections |
Union, 20 mm, PN16
|
Pressure rating |
4 bar
|
Max operating temp. |
55 ºC
|
BACTI-Station Pro, two UviLux fluorometers with Flow Manifolds
Size |
265 x 200 x 200 mm
|
Weight |
5 kg
|
Fluid connections |
Union, 20mm, PN16
|
Pressure rating |
4 bar
|
Max operating temp. |
55 ºC
|
Watchkeeper display and logger
Display |
320 x 240 pixel qVGA backlit LCD
|
Display size |
70 x 50 mm
|
Size |
200 x 110 x 60 mm
|
Weight |
900 g
|
Memory capacity |
2 Gbyte
|
IP rating |
IP67
|
Voltage input |
24 Vdc
|
Power |
2.8 W @ 24 Vdc 4.6 W @ 24 Vdc (Pro)
|
Temperature range |
-20 ºC to 55 ºC
|