www.label.pl | LAB-EL Elektronika Laboratoryjna
Laboratory Electronics

WEIGHTING DRYERS

  • Laboratory measurement of the materials’ humidity
  • The weighting dryers received a distinction during the III International Analytic and Measurement Techniques Fair EUROLAB 2001

DESCRIPTION

A weighting dryer is a laboratory measurement device designed for determining the relative humidity of small samples of different materials. 

The weighting dryer consists of two parts – a precise scale and connected to it a drying chamber with two heating halogen lamps. The drying temperature (set by a user) is regulated by a set of automatic regulation. Additionally the weighting dryer can be equipped with a thermometer, which can be used for:

  • drying temperature control or
  • determining a temperature correction coefficient for a dried material.

Three types of weighting dryers are offered with the technical parameters introduced below. Choosing a particular type depends on a type of work that is to be performed on a certain weighting dryer (only drying or precise weighing). 

When specifying a sample humidity a real drying temperature plays an important role. Its value should closely respond to a set temperature. Another solution is a possibility of drying temperature correction through the correction coefficient.

The latest thing with the weighting dryers is an option enabling two level drying. The process of drying runs automatically for the first drying threshold and then it is switched over to drying in the second scope of temperature.

The weighting dryer is in standard equipped with an interface RS-232, which allows on cooperation with a printer KAFKA 1/Z or a PC computer. When drying the samples the weighting dryer currently sends out the humidity values calculated in the sampling time intervals through the connection RS-232. After finishing the measurements it is also possible to print out a report of drying. The computer programs POMIAR (DOS) and WAGWIN (WIN95) allow on watching a curve of drying (important for stating, whether the sampling is running smoothly), creating a report from the measurements and saving it on a computer disk as well as performing the statistical calculations.

Usage

The properties and usage of the weighting dryers were introduced in an additional description, which discusses the following:

TECHNICAL PARAMETERS

SCALE TYPE WPS 30S WPS  110S WPS  210S
Max load [g] 30 110 210
Min load [mg] 20
Resolution of mass reading [mg] 1
Class accuracy II
Graduation legalisation [mg] 10
Humidity reading resolution [%] 0,01 
Temperature reading resolution 1 °C
Scope of drying temperature 50 ... 160 °C (optionally up to 250°C)
Power of halogens standard 2 x 200W (optionally 2 x 300W)
Sampling time from 1 to 59 seconds
Maximum drying time set    9 hours 59 minutes
Digital displays time of drying, mass (humidity), time of drying
Scope of environment temperature from + 15°C do + 30°C
Output signal    RS 232
Scale pan diameter [mm] 100

EQUIPMENT

  • network cable,
  • five disposable scale pans,
  • built in interface RS-232C,
  • user manual.

EQUIPMENT and FUNCTIONS optionally (upon request):

  • calibration weights,
  • increased scope of drying temperatures up to 250°C,
  • additional disposable scale pans,
  • control thermometer,
  • calibration certificate for a control thermometer (Office of Measures),
  • programs for a cooperating PC computer: POMIAR (DOS) or WAGWIN (WIN95).
GOOD CLIMATE IS FAVORABLE