SS200 Density Gauge

SS200 Density Gauge by Sistec for Slurry & Sludge MeasurementNuclear Density Meter

The SS200 Density Gauge is a Nuclear Density Meter that provides advanced and extremely stable clamp on pipe density gauge with on-board Solids Mass Flow and total solids mass throughout the integrating computer.

This density gauge offers full digital operaiton with automatic gain stabilisation and low source activity. It's rugged construction and IP 67 rating make it the ideal slurry, sewerage, sludge and liquid measurement instrument.

  • Repeatability: 0.0001 SG, 0.00003 SG/ deg. C
  • Power Supply: 24Vdc or 88 to 264 Vac
  • Scintillation Detector
  • Outputs: Density, Per Cent Solids, Solids Mass Flow
  • Optional: 4-20mA, Modbus, Profibus DP, HART
  • AUSTRALIAN MADE Supported by total spares inventory- ex W.A – Next day Service.


Narrow beam geometry
A collimated narrow beam of gamma combined with a collimated NaI scintillation crystal ensures errors due to Compton Scattering through the pipe and slurry do not arrive indirectly at the scintillation crystal.
Decay compensation
Decay compensation is built into the gauge to allow for the decay of the radioactive source. Each day the time elapsed between the last calibration and the present date is used to calculate a correction factor.
Deadtime Correction
In order to achieve accuracy, the count rate period selected must be as high as possible for the accumulation of counts. The electronics used in the density gauge has a finite response time when analysing each pulse as it arrives. When the pulses arrive close together some are not analysed due to earlier pulses still being analysed. The time during which the electronics is unable to analyse pulses is called the deadtime. The software adds the missing counts caused by the deadtime back into the system. For this a wellknown statistical correction formula is used which requires the deadtime to be extremely tightly controlled. The SIStec Model SS200 maintains the deadtime precisely over the temperature range of the instrument, to a precision of ± 10 nanoseconds.
Gain Stabilisation
The SS200 employs a sophisticated control technique which monitors the count rate and compares it to a statistical model of the radiation and automatically adjusts the gain of the detector system accordingly, in effect an automatic gain control.

Principle Components
Source Holder IP65 Lead filled sealed ductile steel or 316 Stainless Steel Shielding meets or exceeds internationally accepted safety standards Rotary shutter with standardising absorber incorporated
Radioisotope Double encapsulated Cs 137 or Co 60
Detector Housing IP67 Rugged steel enclosure or 316 Stainless Steel Connects to Control Unit with instrumentation cable
Scintillation Detector Sodium Iodide with integral photo-multiplier
Control Unit IP66 316 Stainless Steel housing
Switch mode power supply
88-264Vac or 24Vdc 30 Watts
No loss of data with power off
Decay clock continues with power off
Data transmitted by RS422 link
May be up to 1000 metres from detector module
Isolated 4-20 mA current output loops (1.5KV)
Comms options: Modbus RTU, Profibus DP, Device Net, HART Protocol,
Foundation Fieldbus

Operation Specifications
Temperature Drift + 0.000006 SG units per degree Celsius
Repeatability + 0.0001 SG units typical  /  + 0.0002 SG units maximum
Operating Temperature 0 to 60°c
Vibration 2g at 100 Hz
Humidity 5 - 95% RH, non-condensing
Inputs 4 - 20 mA from volume flow gauge
Outputs Two 4 - 20 mA current loops for SC, per cent solids, mass flow, mass flow integrator with potential free contacts, one pulse per tonne
Mass (kg)
Source Holder - 39kg
Dectector Unit - 19kg
Control Unit - 9kg

SS200 Density Gauge Drawing by Sistec