TECHNICAL INFORMATION
16
87-900-120-01 (A)
TECHNICAL CHARACTERISTICS OF THE
PHD-4 BASIC MODULE
Minimum detectable
concentration of He
from 2 ppm (parts for
million)
Minimum detectable He
leak (mbar l/s)
5x10
-6
Minimum detectable He
leak (atm cc/s)
5x10
-6
Minimum detectable He
leak (Pa m
3
/s)
5x10
-7
Reaction time
2 seconds for helium
according to AVS 2.1.
standard
Reading drift
max. 10 ppm every 10
minutes
Measurement readout
Graphic display
RS232
Analogue output
Acoustic signal
Variable frequency
Clean-up time
Average 30 seconds.
Max. 5 minutes (after
helium saturation).
Self-test procedure and
warm-up time
3 minutes
Shut-down time
Immediate
Operating conditions
- temperature
- humidity
+5°C to +35 °C
90% RH (non
condensing)
Jack for headset
Diameter 3.5 mm, mono
or stereo headset (32
Ohm).
Transportability
Using adjustable straps
Weight
2.6kg (5.73 lb)
Dimensions mm
(inches)
Width
170
(6.69)
Height
136
(5.35)
Depth
290
(11.4)
Power supply
18V 1.8A power supply
Battery operative range
4 h
Battery auto discharging
0.1% max. per day at
+20 °C
Battery life
>500 charge/discharge
cycles (IEC standards)
Installation Category
II
Pollution degree
2
Compliance with
EN 61010-1
EN 50270
EN 61000-6-2
EN 61000-6-3
Relay contacts:
-
Voltage
-
Max
current
24 Vac/cc
1 A (resistive load)
0,3 A (inductive load)
Input FZ/AZ:
-
Pin 8: positive
-
Pin 1: ground
Pins 8-1 closed: AZ
Pins 8-1 open: FZ
Sensor protection
The sensor is protected against excess flow of helium
by the so-called "protection set-point" (inside the set-
point icon
, identified by the number "5").
This function can be used to determine the safety
threshold above which the sensor is protected (see
table below) activating the most suitable type of
protection according to the test in progress.
Protection set-point levels
Low
sensitivity
High
sensitivity
Minimum value
(ppm)
200
2
Default value
(ppm)
400
100
Maximum value
(ppm)
600
250
Each time the protection level is exceeded during
measurement, the "protection set-point" is activated
and the user is alerted with a message on the display
and an acoustic signal (see graphs below).
t
Backflow Valve
Position
Quartz Heater
Status
2 sec
OFF
2
x
ppm
Backflow Valve
Normal
Backflow Valve
Reverse
DISPLAY
Valve
Normal
Valve
Normal
Valve
Reverse
ON
ON
“LEAK
!”
Tripping of the "protection set-point" may also trigger
an active protection at one or two levels.
