KOBOLD KFF/KFG Rotating Vane Low Volume Flow meter

KOBOLD KFF/KFG Rotating Vane-Low Volume are used for measuring low and smaller, volumetric flow rates of gases (KFG) and liquids (KFF). The media must be transmissive for infrared light.

Series KFF/KFG 1000 flowmeters are available in Ryton®, brass and PTFE materials; therefore suitable for many applications in industry, in laboratories, and so forth. The new PTFE sensor of the 1000 series is delivered as standard with (0 … 5 VDC) analogue output and frequency output. The frequency output is optional on other models. Series KFF/KFG 3000 flowmeters are available in Ryton® and in brass.

Kobold Rotating Vane-Low Volume — Rotating Vane-Low Volume KFF-1, KFG-1

Measuring Range:

15 – 100 ml/min … 1 – 10 l/min water
25 – 100 ml/min … 100 – 500 l/min air

Connection: G ⅛ … G ½
Material: brass, Ryton^®, PTFE
p_max: 35 bar
t_max: 50°C
Accuracy: ±3 % of full scale
Viscosity range: low viscosity
Pulse output, 0 – 5 V_DC

Measuring range:

15 – 100 ml/min … 1 – 10 l/min water
25 – 100 ml/min … 100 – 500 l/min air

Connection: G ⅛ … G ½
Material: PPS, brass, PTFE
p_max: 35 bar
t_max: 50°C
Accuracy: ±3 % of full scale
Viscosity range: low viscosity Digital display, 0 – 5 V_DC

KOBOLD KFF/KFG Function Principle

The flowmeter is based on the Pelton Principle, that is, the flowing medium causes a vane to rotate. The rotary motion is converted to electrical impulses by means of photodiodes. The flow rate is output as a frequency signal or a linear analogue (0…5 VDC).

KOBOLD KFF/KFG Specifications

Technical Data

Accuracy: ± 3 % f. s.
Linearity: ± 3 % f. s.
Repeatability:
- KFF: ± 0.2 % f. s.
- KFG: ± 1% f. s.
Installation position: horizontal
Temperature range: 0…50°C
Temperature drift: 0.2%/ °C
Max. pressure:
- KFF:
- Ryton®: 7 bar
- Brass: 35 bar
- PTFE: 4 bar
- KFG: 2.5 bar
Supply voltage: 12.5 VDC ± 2 VDC
PTFE version: 12.5 VDC ± 1 VDC
Current consumption: 50 mA (typically)
Output:
- KFF-1../KFG-1..:
- Standard: 0…5 VDC
  Option T
- (KFF-1.. only): 0…5 VDC and frequency output
- PTFE version: 0…5 VDC and frequency output
Max. frequency: 500 Hz
KFF-3../KFG-3..: 0…5 VDC

Material

Version	Ryton®	Brass	PTFE
Housing	60% Ryton®/ 40% glass	Brass/grass	PTFE
Turbine	60% Ryton®/ 40% glass	60% Ryton®/ 40% glass	PTFE
Bearings	Sapphire	Sapphire	Sapphire
Bearing Shell	St. steel (316)	St.steel (316)	PTFE
Gasket	FPM	FPM	Kalrez®
Connection	Acetal	Brass	PFA