Thermometers Direct

Zeal Whirling Hygrometer Sling Psychrometer P2528

(Inc. 20% VAT)
(£36.00 Exc. VAT)
(3 Reviews)
16 in stock, immediate despatch
Product Code
Part Number
Zeal Thermometers

Zeal Whirling Hygrometer Sling Psychrometer

The Zeal Whirling Hygrometer Sling Psychrometer offers the maximum level of accuracy for the measurement of relative humidity utilising wet and dry bulb Red Spirit filled thermometers.  The unit incorporates a water reservoir linked to the wet bulb by the means of a cotton sleeve. The Humidity is calculated using a water-soaked cotton sleeve at the bulb of the wet-bulb thermometer, how quickly the water evaporates alters the temperature of the wet-bulb thermometer. Using the specialist chart included allows you to calculate the relative humidity.


  • Measures Humidity through the measurement of air temperature
  • Mercury free


  • Temperature range: -5 to +50°C to calculate the %RH

  • Humidity: +-5%
  • Temperature: +- 1oC
PLEASE NOTE: Product may differ from image. This is a Mercury free thermometer.

Other products you may be interested in:

Zeal Spare Whirling Tube Spare thermometer
Carry pouch For Whirling Hygrometer

Customer Reviews (3)
Write a Review and share your opinions!
3 Reviews:

Functional, but build quality is terrible
11 March 2017  | 

When I tried to fill the water reservoir for the first time, the water ran out of it as fast as I was filling it.

I disassembled the end of the hygrometer to remove the reservoir and found that the 'tube' that leads from the reservoir towards the wet bulb thermometer was not sealed into the reservoir. (I use the term tube loosely, as it looks like a short piece of heat-shrink sleeving has been used.) Image can be seen here:

I remedied the issue by applying a small amount of rapid-setting two-part epoxy resin around where the tube penetrates the reservoir to form a seal. Once this had had sufficient curing time, I reassembled the instrument, refilled the reservoir and it held water.

Was this helpful to you?  Yes  /  No

23 July 2016  | 

First class service

Was this helpful to you?  Yes  /  No

20 February 2015  | 

good value

Was this helpful to you?  Yes  /  No
Delivery Costs

Shipping And Handling

1st Class post up to 14 days for delivery Long delays due to Covid-19

Carrier Service 1-14 days, is an estimated day of delivery is given when you place a order.

Delivery can be from 8.30am to 6pm

Please note all shipping is PER ORDER , NOT PER ITEM

Next day delivery is extra but we can not be held liable for the carriers delaying the (WEEKENDS AND BANK HOILIDAYS ARE NOT INCLUDED IN WORKING DAYS). Highlands and Islands / IV BT, IM TR 21-25, HS, KA27,28, KW1-3, 5-15, PA20-49, 62-77,61,78,PH17-26, 30-44, 49-50, ZE1-3 postcodes takes 48 hour

We must have the order by 3pm to have a chance of getting the order out the same day ( AS LONG AS GOODS ARE IN STOCK) Next day not available for European Orders

ORDERS OVER £65 POST FREE (Excluding European Orders)

For those orders over £65 we will send Post Free. To 1 address if more then 1 address per order, a delivery charge either £6.96 or £3.60 will be added
Once the parcels have left our premises the responsibility for delivery is with the Royal Mail or our Carrier.

We are not responsible for late delivery's that may of happened once the parcel has left us as we will try and get the parcel out to you as fast as we can. Please contact us if any problems, problems do happen but we are always here to help.
Or if you are still waiting for a parcel (over 10 working days Royal Mail) please let us know so we can sort out the problem.
Orders are dispatched by post / carrier to the name and address you have given to us. If we have received incorrect or inadequate information for the delivery of the goods we cannot accept any liability for late or failed delivery as a result of this.

Delivery Schedule We process your order right away. We will normally send your order to you in 2 - 5 business days . International orders are generally received in under 10 days.
Does not Include Trade Orders OR Purchase Orders

A calibrated thermometer if ordered in error / or not wanted can only be returned upto 14 days after purchase because the certificate has a expiry date

Purchase Orders

We accept Orders from Government based purchases, we regularly supply the following organisations

  • Hospitals, PCT's, NHS Foundation Trusts
  • Police Force, Fire Service
  • Councils
  • Prison Service
  • All British Military Forces

There is £50 minimum order value for purchase order

P&P on all Purchase Orders under £65 (ex Vat) £5.42+VAT
P&P will be free on Orders over £65 (ex vat)

Send your order by Email:-

Payment must be made within 30 days by BACS or Cheque