Product guide

31
Humidity and Dew-Point Instruments
Please note: Michell Instruments adopts a continuous development program which sometimes
necessitates specifi cation changes without notice. Please contact us for latest version.
www.michell.com
Calibration
MDM25
Hand-Held Hygrometer
The MDM25 is a portable, battery-operated handmeter, and
is available with a number of different probe confi gurations.
It displays relative humidity, temperature and one calculated
value, making this handmeter suitable for a wide range of
applications. The user can choose to display either ºC or ºF.
Highlights
• Displays %RH and temperature, plus dew point, absolute
humidity and wet bulb temperature
• Simple to operate
• Long term stability: ±1% RH over 12 months
Technical Specifi cations:
Hand Meter
Performance
Measurement units %RH, °C/°F Ta, °C/°F Td, g/m
3
, °C/°F Tw
Mechanical specifi cation
Ingress protection IP54 - Hand meter only
Handmeter housing material Molded polymer housing ABS + rubber
surround
Weight 300g (10.58oz)
Display resolution Graphic LCD 128 x 64 pixels
Electrical output/input
Supply voltage 4.5 V
(3 x AA batteries - provide approximately 70
hours of operation)
Electrical connections M9 5-way triad connector
Probes
Performance
Measurement range (RH) 0 - 100% RH
Accuracy at 25ºC (77ºF)
Temperature
< ±0.2ºC (±0.36ºF)
Stability - RH Sensor ±1% RH/year
Response time - RH Sensor <10 sec typical (for 90% of the step
change)
Measurement & operating
range (T)
Fixed and Standard probe
Sword probe
Remote probe
-20 to +80°C (-4 to +176°F)
-20 to +100°C (-4 to +212°F)
-20 to +150°C (-4 to +302°F)
Accuracy at 25ºC (77ºF)
Humidity - Fixed probe
- Remote probes
±2% RH (10 - 90% RH)
±2% RH (5 - 95% RH)
Mechanical specifi cation
Weight:
Fixed Probe
Standard Probe
Sword Probe
Round 300mm probe
Round 500mm probe
FPR
SPR
SWPR
HTPR300
HTPR500
30g (1.06 oz)
90g (3.17 oz)
500g (1.1 lb)
380g (13.4 oz)
620g (1.37 lb)
Issue No: MDM25_97227_V1.4_UK_1211
Accessories and Spare Parts
19mm (0.75”) slotted protection cap black A000002
12mm (0.47”) Slotted protection cap, black
A000003
19mm (0.75”) PVDF fi lter
A000014
12mm (0.47”) PVDF fi lter
A000017
12mm (0.47”) PVDF fi lter with protection cap, black
A000018
19mm (0.75”) mesh fi lter with protection cap, black
A000021
12mm (0.47”) Mesh fi lter with protection cap, black
A000022
12mm (0.47”) Flat SS sintered dust fi lter
A000023
19mm (0.75”) Arrow SS sintered fi lter 10m
A000026
12mm (0.47”) Arrow 20 m SS sintered fi lter
A000028
Rubber surround for hand meter case
A000400
Carrying case
A000401
Batteries (3 AA Alkaline cells)
A000402
Fixed probe
MDM-FPR
Standard probe
MDM-SPR
Sword type probe
MDM-SWPR
Remote high temperature probe 300mm (18”)
MDM-HTPR
Remote high temperature probe, 500mm (19.6”)
MDM-HTPR
You can check your hygrometer with the Control Kit HKC which
is based on the principle of non-saturated salt solutions. Refer to
technical data sheet CONTROL KIT
HKC