Vaisala HMP230 Series Instrukcja Użytkownika Pobierz pdf (Strona 4)

CALIBRATION

The transmitter software also includes

a procedure for calibrating the

relative humidity and temperature.

The calibration can be done either

by making a fast one-point adjust-

ment in the field against a reliable

reference instrument, such as Vaisala's

humidity data processor HMI38, or a

two-point calibration in a controlled

environment e.g. with a salt bath

calibrator such as Vaisala's HMK15

calibrator.

The calibration interval depends on

the application where the transmitter

is used. In normal conditions

calibration once year is

recommended.

TRANSMITTER PROTECTION

The housing of the HMP230

transmitters is made of aluminium

which provides IP 65 protection

from dust and sprayed water.

The housing also provides protection

from electromagnetic interference.

The cables used are all protected from

electromagnetic interference either to

3 V/m or 10 V/m. However, the

electromagnetic compatibility of the

sensor heads depends on the filters

fitted. See General Techical

Information for all cable/filter

combinations.

CONFIGURED TO YOUR

REQUIREMENTS

The HMP230 transmitters are

extremely flexible products which can

be configured in many ways – both

in hardware and software. They are

manufactured on a production line

where they are configured to the

customer requirements. The user does

not need to change any transmitter

settings when installing the

instrument unless the application has

chang-ed in some way. If so, the

settings of the HMP230 transmitters

are easy to change even in the field.

SETTINGS AND ADJUSTMENTS

MADE EASY

The HMP230 transmitters have

several output variables to choose

from. They, like the other settings,

are easy to change. Selecting, scaling

and calibrating the analogue output

signals and parameters can be done

in a few minutes using simple

software commands.

This can be done by using the

menus on the local display or with a

PC or terminal connected to the

transmitters’ serial bus.

The microprocessor-based transmit-

ters measure the relative humidity

and temperature. From these two

measurements other variables –

dewpoint temperature, wet bulb

temperature, absolute humidity,

mixing ratio and enthalpy – can be

calculated depending on the

transmitter version. The transmitters

have two analogue output channels

and any two of the seven measured

or calculated variables can be selected

as output signals.

The measurement ranges and the

output signals can be selected and

scaled within certain limits which

depend on the maximum

measurement range. For example, the

standard temperature measurement

range of the HMP235 is

-40...+180 °C, but it can easily be

scaled so that -20...+100 °C

corresponds to 0...20 mA or any

other output signal.

Reliability & Flexibility

1 2 3 4 5 6 7 8

Komentarze do niniejszej Instrukcji

Brak uwag