GELNORM® – RVN Pot life measurement
GELNORM® – RVN Pot life measurement
Product Code : GELNORM-RVN
Brand Name : GEL INSTRUMENTE
GELNORM® – RVN
Pot life measurement
Gelnorm®- RVN is an instrument for the automat-ic determination of the pot life of reaction resins based on the measurement of the relative viscos-ity. Applications include:
· Unsaturated polyster resins
· Epoxy resins
· Polyurethane resins
· Acrylate resins
· Silicone resins
· Polysulfide rubbers
· Silicone rubbers
GELNORM® - RVN can be used for structurally viscous, thixotropic and very slow hardening reaction resins. Highly filled systems such as primers and fillers can be tested with this instrument as well as adhesives.
The measurement of the viscosity increase follows in general the DIN 16 945, page 1 point 6.1. Ac-cording to this standard, the time is determined to reach an agreed upon viscosity limit. This limit is depending on the handling and working process of the resin and shall be determined by producer and user.
The tests with GELNORM® - RVN are performed automatically and under standardized and reproduc-ible conditions. The change of viscosity in the sample is determined by the power increase required by a periodically rotating spindle probe. All results remain stored and can be replotted until the next expe-riment is started. Using a special program, the data can be transmitted to a computer for further data analysis using MS-EXCEL.
Five different viscosity limiting values can be preselected and, hence, individual pot lifes or processing times can be determined simply and without plotting the whole curing experiment.
In order not to influence the structure of the sample during the measurement, the instrument operates with only short measurement cycles (3 sec) and interval cycles the length of which can be adjusted between 0 sec and 120 min.
For the simultaneous determination of the temperature in addition to the relative viscosity, the GEL-NORM®-Therm-Box I (ref. 160.81) with an attached Ni-Cr-Nithermopile is connected to the control unit. The thermopile is inserted into the reaction resin together with the probe at the beginning of the test.
GELNORM® - RVN was especially developed for the determination of pot life. Its performance and accuracy is designed for this purpose.
DESCRIPTION OF INSTRUMENT
GELNORM® - RVN (Ref. 30.05) consists of a control unit which is based on a process controlled mea-suring system and a probe drive with a rotating spindle, fig. 1. Two different probe drives with viscosity limits of 100’000 mPa. s (Ref. 30.10) and 400’000 (Ref. 30.11) are available.
A liquid crystal display is used to display all functions and parameters. All selections and inputs can be made by a menu-driven program.
All relative viscosities determined with GELNORM® - RVN can be calculated to absolute viscosities by the aid of newtonian calibration fluids. The limit viscosity for stopping the instrument can be deter-mined by separate manual one time operations or with calibrations. (0 - 100%).
TEMPERATURE CONTROL SYSTEM
A prerequisit for an exact and reproducible determination of the pot life with GELNORM® - RVN is a high precision thermostatic system. For temperatures up to 120 °C we recommend a thermostatic bath, up to 200 °C our Heating Block GT in connection with our temperature controller TC-3.
1. Thermostatic Bath
By submersing the test tube (180 x Ø 20 mm) with the sample into a thermostatic bath, tests can be performed at defined t
emperatures between 20 and 120 °C. For special requirements there are baths for testing at temperatures between -20 and +180 °C available.
2. Electric Heating Block GT
At temperatures of 50 up to 200 °C our Electric Heating Block GT (Ref. 20.41a) can be used. Temperature control of the heating block is performed with the temperature controller TC-3 (Ref. 70.05).
Power supply 230 V / 50 Hz or 115 V / 60 Hz, ± 10 %,
PC RS-232, 9600 Baud D-Sub Plug
Fuses I = 500 mA; II = 2 A
Probes Typ 7811: for low visc. Typ 7835: for high visc.
Measuring principle Process controlled measuring system
Program memory Eprom
Data memory Battery-RAM
Time/Date actual time module